Barack Obama is sworn in as the 44th President of the United States on January 20, 2009. Click through the gallery to see 100 moments from his administration. Chuck Kennedy/Getty Images

The Obamas share a moment on a freight elevator as they head to one of the inaugural balls on January 20, 2009. "It was quite chilly, so the President removed his tuxedo jacket and put it over the shoulders of his wife," White House photographer Pete Souza said. "Then they had a semi-private moment as staff members and Secret Service agents tried not to look." Pete Souza/The White House

Obama wears 3-D glasses during a Super Bowl viewing at the White House on February 1, 2009. Pete Souza/The White House

Obama speaks with aides in the White House Oval Office on February 4, 2009. From left are Senior Advisor Pete Rouse, White House Director of Legislative Affairs Phil Schiliro, Senior Advisor David Axelrod, National Economic Council Director Lawrence Summers and White House Chief of Staff Rahm Emanuel. Pete Souza/The White House

Vice President Joe Biden watches Obama sign the economic stimulus bill on February 17, 2009. The goal was to stimulate the country's staggering economy by increasing federal spending and cutting taxes. Darin McGregor/AP

Obama acknowledges applause before addressing a joint session of Congress for the first time on February 24, 2009. The President focused on the three priorities of the budget he presented to Congress later in the week: energy, health care and education. Pablo Martinez Monsivais/AP

A boy touches Obama's hair in the Oval Office on May 8, 2009. "A temporary White House staffer, Carlton Philadelphia, brought his family to the Oval Office for a farewell photo with President Obama," White House photographer Pete Souza said. "Carlton's son softly told the President he had just gotten a haircut like President Obama, and asked if he could feel the President's head to see if it felt the same as his." Pete Souza/The White House

Obama kisses Sonia Sotomayor after announcing her as a Supreme Court nominee on Tuesday, May 26. Sotomayor went on to become the court's first Hispanic justice. Joshua Roberts/Bloomberg/Getty Images

The President returns to the Oval Office after going on a hamburger run for West Wing staffers and aides on May 29, 2009. Chuck Kennedy/The White House

Obama closes his eyes before taping his weekly radio address at the White House on June 2, 2009. Pete Souza/The White House/Getty Images

Obama tours the Great Pyramid and Sphinx in Giza, Egypt, on June 4, 2009. In a speech at Cairo University, Obama pledged to "seek a new beginning between the United States and Muslims around the world," imploring America and the Islamic world to drop their suspicions of one another and forge new alliances. Stephen Crowley/The New York Times/Redux

Obama places a flower at the Buchenwald Memorial as he visits the former concentration camp in Germany on June 5, 2009. Pete Souza/The White House

Sasha Obama hides behind an Oval Office sofa as she sneaks up on her father on August 5, 2009. Sasha was 7 when her father took office. Malia was 10. See more pictures of Malia and Sasha Obama since their father was elected President Pete Souza/The White House/Getty Images

Obama stands on stage before delivering remarks to service members in Jacksonville, Florida, on October 26, 2009. "Of all the privileges I have as President, I have no greater honor than serving as your commander in chief," Obama said in his speech. Pete Souza/The White House

Obama salutes during the dignified transfer of Army Sgt. Dale R. Griffin on October 29, 2009. The President traveled to an Air Force base in Dover, Delaware, to meet a plane carrying the bodies of 18 Americans killed in Afghanistan. SAUL LOEB/AFP/Getty Images

The President fist-bumps custodian Lawrence Lipscomb in the Eisenhower Executive Office Building on December 3, 2009. Pete Souza/The White House

Obama poses with a diploma and gold medal after accepting the Nobel Peace Prize in Oslo, Norway, on December 10, 2009. The Norwegian Nobel Committee said it honored Obama for his "extraordinary efforts to strengthen international diplomacy and cooperation between peoples." Obama was the fourth U.S. President to win the Nobel Peace Prize. Theodore Roosevelt, Woodrow Wilson and Jimmy Carter also received the award. OLIVIER MORIN/AFP/Getty Images

The President talks on a cell phone as he steps off Marine One in Baltimore on January 29, 2010. Charles Dharapak/AP

Obama plays with his daughters in the White House Rose Garden during a snowstorm on February 6, 2010. Pete Souza/The White House

Obama calls a member of Congress to discuss health care reform on March 19, 2010. A bill passed the Senate in December 2009, but there were intense negotiations before it could pass the House. The bill passed 219-212 after more than a year of bitter partisan debate. All 178 Republicans opposed it, along with 34 Democrats. Pete Souza/The White House

Obama signs the Affordable Care Act -- his health care overhaul -- on March 23, 2010. It was the biggest expansion of health care guarantees in more than four decades, and it represented a significant step toward the goal of universal coverage, which has been sought by every Democratic President since Harry Truman. Doug Mills/The New York Times/Redux

Obama takes the stage on a rainy day outside of Chicago on May 31, 2010. He was scheduled to give a Memorial Day speech. "When the lightning began, the Secret Service told the President that it was too dangerous to proceed," White House photographer Pete Souza said. "He took the stage by himself and informed the audience that his speech was canceled and that for everyone's safety, they should return to their buses. Later, he boarded a few of the buses to thank them for attending and apologized for not being able to speak." Pete Souza/The White House

Obama takes questions at the G-20 Summit in Toronto on June 27, 2010. "We came to Toronto with three specific goals: to make sure the global (economic) recovery is strong and durable; to continue reforming the financial system; and to address the range of global issues that affect our prosperity and security. And we made progress in each of these areas," Obama said. Pete Souza/The White House

The President puts his toe on a scale as White House travel director Marvin Nicholson tries to weigh himself in Austin, Texas, on August 8, 2010. Pete Souza/The White House

Obama hosted a working dinner with Mideast leaders on September 1, 2010. With Obama, from left, are Egyptian President Hosni Mubarak, Israeli Prime Minister Benjamin Netanyahu, Palestinian Authority President Mahmoud Abbas and Jordan's King Abdullah II. Obama said he was "cautiously hopeful" that talks could achieve a two-state solution to the long-running Mideast conflict. Charles Dharapak/AP

Obama shoots baskets before speaking at Cleveland State University on October 31, 2010. Pete Souza/The White House

The President greets U.S. troops after an unannounced flight to Afghanistan on December 3, 2010. The U.S. combat mission ended in Afghanistan in December 2014, but American troops remain in the country to support Afghan forces and counterterrorism operations. Pete Souza/The White House

Obama prays in the Oval Office with co-chairs of the National Prayer Breakfast on January 27, 2011. From left are U.S. Rep. Heath Shuler, U.S. Rep. Tom Coburn, U.S. Rep. Jeff Miller, Obama, former Arizona Rep. Ann Kirkpatrick and U.S. Sen. Mark Pryor. Pete Souza/The White House

The first family tours the Christ the Redeemer statue in Rio de Janeiro on March 19, 2011. Obama visited Brazil, Chile and El Salvador during his trip to Latin America. Pete Souza/The White House

Obama talks with Vice President Joe Biden after a teleconference call about Libya on April 5, 2011. Obama committed U.S. forces to the U.N.-authorized mission in Libya, and he told the American people there were strategic and moral reasons to act. Failure to do so, he said, would have allowed Libyan leader Moammar Gadhafi to unleash his military on his own people. Pete Souza/The White House

Obama and members of his national security team monitor the mission against Osama bin Laden on May 1, 2011. "Fourteen people crammed into the room, the President sitting in a folding chair on the corner of the table's head," said CNN's Peter Bergen as he relived the bin Laden raid five years later. "They sat in this room until the SEALs returned to Afghanistan." (Editor's note: The classified document in front of Hillary Clinton was obscured by the White House.) Pete Souza/The White House

Obama and the first lady enjoy a glass of Guinness as they visit his ancestral home of Moneygall, Ireland, on May 23, 2011. Moneygall is believed to be the birthplace of one of his great-great-great grandfathers. Irish Government/Pool/Getty Images

Obama and British Prime Minister David Cameron play table tennis with students in London on May 24, 2011. JEWEL SAMAD/AFP/Getty Images

During his state visit to England, Obama was also able to meet with Queen Elizabeth II and Prince Philip. The first couple gave the queen a handmade leather-bound album with rare memorabilia and photographs that highlighted the visit by her parents -- King George VI and Queen Elizabeth -- to the United States in 1939. To Prince Philip, they gave a custom-made set of pony bits and shanks and a set of horseshoes worn by a recently retired champion carriage horse. The Obamas were given copies of letters in the royal archives from a number of U.S. presidents to Queen Victoria. Michelle Obama also was given an antique broach in the form of roses made of gold and red coral. Allpix/Splash News/Newscom

Obama greets Hugh Hills, 85, in front of Hills' tornado-damaged home in Joplin, Missouri, on May 29, 2011. It was the deadliest tornado to hit American soil since the National Weather Service began keeping records in 1950. Nearly 160 people were killed. Pete Souza/The White House

Obama talks backstage with Senior Advisor Valerie Jarrett before a reception in Philadelphia on June 30, 2011. Pete Souza/The White House

Obama shakes the prosthetic hand of Army Sgt. 1st Class Leroy Arthur Petry on July 12, 2011. Petry was at the White House to receive the Medal of Honor. The Army Ranger lost his hand while tossing an enemy grenade away from fellow soldiers in Afghanistan. Charles Dharapak/AP

Obama does pushups on the White House basketball court after a member of the Harlem Globetrotters made a shot on April 9, 2012. Pete Souza/The White House

During an event on April 18, 2012, Obama looks out of the famous Rosa Parks bus that was restored by the Henry Ford Museum in Dearborn, Michigan. "I just sat in there for a moment and pondered the courage and tenacity that is part of our very recent history but is also part of that long line of folks who sometimes are nameless, oftentimes didn't make the history books, but who constantly insisted on their dignity, their share of the American dream," the President said. Pete Souza/The White House

Obama congratulates cadets as they receive their diplomas from the U.S. Air Force Academy on May 23, 2012. Pete Souza/The White House

The Obamas take in the Chicago skyline on June 15, 2012. The Obamas lived in Chicago before he was President, and they still own a home there. Pete Souza/The White House

Obama faces off with Mitt Romney at a presidential debate in Hempstead, New York, on October 16, 2012. Obama was re-elected with 332 electoral votes to Romney's 206. Charlie Neibergall/AP

Obama pretends to be caught in Spider-Man's web as he interacts with Nicholas Tamarin, 3, just outside the Oval Office on October 26, 2012. Nicholas, son of White House aide Nate Tamarin, had been out trick-or-treating. "The President told me that this was his favorite picture of the year when he saw it hanging in the West Wing a couple of weeks later," White House photographer Pete Souza said. Pete Souza/The White House

Obama takes the oath of office during his swearing-in ceremony on January 21, 2013. He is the 17th President to win a second term. Pete Souza//The White House

Obama kisses his wife during the inaugural parade in Washington. Sasha, left, takes a photo of her sister, Malia. Gerald Herbert/AP

The President takes a tour of the ancient city of Petra during a visit to Jordan on March 23, 2013. He was accompanied by a University of Jordan tourism professor, and all other visitors kept well away -- except for a few stray cats. Pete Souza/The White House

Obama and four former U.S. Presidents attend the dedication of the George W. Bush Presidential Center and Museum on April 25, 2013. From left are Obama, Bush, Bill Clinton, George H.W. Bush and Jimmy Carter. Pete Souza/The White House

Obama looks to see if it's still raining at a White House news conference on May 16, 2013. Charles Dharapak/AP

Obama takes a photo with a sleeping boy at the White House during a Father's Day ice cream social on June 14, 2013. Pete Souza/The White House

Obama and the first lady tour an old slave house on Senegal's Goree Island on June 27, 2013. It was part of a three-nation tour in Africa. "For an African-American -- and an African-American President -- to be able to visit this site, I think (it) gives me even greater motivation in terms of the defense of human rights around the world," Obama said. Pete Souza/The White House

Bo, one of the Obamas' dogs, hangs out in the Outer Oval Office as the President begins his day on November 6, 2013. "Each morning, the President always enters through this door rather than the direct outside door to the Oval Office," White House photographer Pete Souza said. Pete Souza/The White House

Advisers Ben Rhodes, left, and Tony Blinken show their approval as Obama discusses Iran negotiations with Secretary of State John Kerry on November 23, 2013. Two years later, after arduous talks that spanned 20 months, negotiators reached a landmark deal aimed at reining in Iran's nuclear program. The essential idea behind the deal is that in exchange for limits on its nuclear activities, Iran would get relief from sanctions while being allowed to continue its atomic program for peaceful purposes. Pete Souza/The White House

Obama and British Prime Minister David Cameron pose for a selfie with Danish Prime Minister Helle Thorning-Schmidt during Nelson Mandela's memorial service in Johannesburg on December 10, 2013. Some thought it was tasteless, considering the occasion. ROBERTO SCHMIDT/AFP/Getty Images

Obama tosses a football in the Oval Office on January 6, 2014. Pete Souza/The White House

Obama greets locals in Phoenix after touring a model home of a nonprofit's housing development on January 8, 2014. Pete Souza/The White House

Obama works on his computer aboard Air Force One on February 19, 2014. Pete Souza/The White House

Aides laugh as the President swats a fly in the Oval Office on May 6, 2014. Pete Souza/The White House

Obama slides across a counter to pose with staff members at a Shake Shack restaurant in Washington on May 16, 2014. Vice President Joe Biden, lower right, also did the same. "The President normally does a group photo with restaurant staff when he stops for lunch or dinner," White House Photographer Pete Souza said. Pete Souza/The White House

Obama, center, walks with the parents of Army Sgt. Bowe Bergdahl after making a statement about Bergdahl's release on May 31, 2014. Bergdahl had been held captive in Afghanistan for nearly five years, and the Taliban released him in exchange for five U.S.-held prisoners. Jacquelyn Martin/AP

The President sits for a 3-D-printed bust being produced by the Smithsonian Institution on June 9, 2014. See the final product from the White House Maker Faire, which highlighted the importance of 3-D printing and other technologies that help people design and build new things. Pete Souza/The White House

Obama tries out a driving simulator July 15, 2014, as he tours the Turner-Fairbank Highway Research Center in McLean, Virginia. The simulator was meant to demonstrate the types of "smart" vehicles being developed at the center. Jacquelyn Martin/AP

The President delivers a statement on the unrest in Ferguson, Missouri, on August 18, 2014. The St. Louis suburb was in turmoil after Darren Wilson, a white police officer, fatally shot Michael Brown, an unarmed black teenager. "Ours is a nation of laws: of citizens who live under them and for the citizens who enforce them," Obama said. "So, to a community in Ferguson that is rightly hurting and looking for answers, let me call once again for us to seek some understanding rather than simply holler at each other. Let's seek to heal rather than to wound each other." Doug Mills/The New York Times/Redux

Obama leaves the White House briefing room after speaking about various topics on August 28, 2014. But the reaction on Twitter was largely focused on his rarely worn tan suit. Evan Vucci/AP

Obama visits Stonehenge on September 5, 2014. White House photographer Pete Souza recalled that day: "We were at the NATO summit in Wales when someone mentioned to the President that Stonehenge wasn't that far away. 'Let's go,' he said. So when the summit ended, we took a slight detour on the way back to Air Force One." Pete Souza/The White House

Obama and Indian Prime Minister Narendra Modi visit the Martin Luther King Memorial in Washington on September 30, 2014. Alex Wong/DPA/AP

Obama hugs Ebola survivor Nina Pham in the Oval Office on October 24, 2014. Pham, one of two Dallas nurses diagnosed with the virus, was declared Ebola-free after being treated at a hospital in Bethesda, Maryland. The other nurse, Amber Vinson, was treated in Atlanta and also declared Ebola-free. Evan Vucci/AP

The President walks along the White House Colonnade on January 22, 2015. Chuck Kennedy/The White House

Obama delivers remarks at the Edmund Pettis Bridge on the 50th anniversary of "Bloody Sunday," when marchers were brutally beaten in Selma, Alabama, as they demonstrated for voting rights in 1965. Pete Souza/The White House

Obama poses with the world's fastest man, Jamaican sprinter Usain Bolt, at an event in Kingston, Jamaica, on April 9, 2015. Pete Souza/The White House

Obama's wave aligns with a rainbow as he boards Air Force One in Kingston, Jamaica, on April 9, 2015. Pete Souza/The White House

Obama says goodbye to House Minority Leader Nancy Pelosi from a West Wing hallway on April 29, 2015. Pete Souza/The White House

The President speaks at a White House event that recognized emerging global entrepreneurs on May 11, 2015. DOUG MILLS/The New York Times/Redux

German Chancellor Angela Merkel talks with Obama near the Bavarian Alps on June 8, 2015. Obama and other world leaders were in Germany for the annual G-7 Summit. "Merkel asked the leaders and outreach guests to make their way to a bench for a group photograph," White House Photographer Pete Souza said. "The President happened to sit down first, followed closely by the Chancellor. I only had time to make a couple of frames before the background was cluttered with other people." Pete Souza/The White House

Obama takes a photo with the "Racing Presidents" of the Washington Nationals baseball team on June 11, 2015. The mascots, which race at every Nationals home game, represent former U.S. Presidents -- from left, George Washington, Thomas Jefferson, William Howard Taft, Theodore Roosevelt and Abraham Lincoln. "The President asked the Secret Service to stop the motorcade when he spotted The Racing Presidents," White House Photographer Pete Souza said. Pete Souza/The White House

Obama sings "Amazing Grace" during services honoring the life of South Carolina state Sen. Clementa Pinckney on June 26, 2015. Pinckney was one of nine people killed in a church shooting in Charleston, South Carolina. David Goldman/AP

Obama greets audience members after speaking in Nairobi, Kenya, on July 26, 2015. He was making his first visit to his father's homeland as commander in chief. Pete Souza/The White House

The President and first lady escort Pope Francis back inside the White House after an arrival ceremony on September 23, 2015. The Pope was on a six-day visit of the United States that also scheduled stops in New York and Philadelphia. David Lienemann/The White House

Obama was playing golf in La Jolla, California, where a wedding ceremony was about to begin on October 11, 2015. "The bride and groom were waiting inside, but when they looked out the window and saw the President, they decided to make their way outside," White House photographer Pete Souza said. Souza sent a copy of the photograph to the couple, Brian and Stephanie Tobe. "Both wrote back to me that they were extremely grateful to have the President 'crash' their wedding." Pete Souza/The White House

Obama holds Ella Rhodes, daughter of Deputy National Security Advisor Ben Rhodes, in the Oval Office on October 30, 2015. She was wearing an elephant costume for a Halloween event at the White House. Pete Souza/The White House

Comedian Jerry Seinfeld knocks on the Oval Office window December 7, 2015, during a taping of his series "Comedians in Cars Getting Coffee." The two drove around the White House in a 1963 Corvette Stingray, drank coffee and talked politics in the episode. Pete Souza/The White House

The President and the first lady meet R2-D2 and a stormtrooper for a White House screening of the new "Star Wars" movie on December 18, 2015. Lawrence Jackson/Zuma Press/Newscom

Obama cries as he talks about the victims of the Sandy Hook school shooting during a White House news conference on January 5, 2016. "Every time I think about those kids, it gets me mad," he said, referring to the 2012 massacre that killed 26 people in Connecticut. Obama, calling for a national "sense of urgency," unveiled a series of executive actions on guns, including expanded background checks. DOUG MILLS/The New York Times/Redux

The Obamas greet Virginia McLaurin, 106, before a White House reception celebrating African-American History Month on February 18, 2016. McLaurin was so excited that she started dancing, and the video went viral. Lawrence Jackson/The White House

Obama walks past House Speaker Paul Ryan in Washington during a St. Patrick's Day lunch with Irish Prime Minister Enda Kenny on March 15, 2016. Pablo Martinez Monsivais/AP

Cuban President Raul Castro tries to lift up Obama's arm at the end of a joint news conference in Havana, Cuba, on March 21, 2016. Obama became the first sitting U.S. President to visit Cuba since 1928, and he called for the U.S. embargo against Cuba to be lifted. Ramon Espinosa/AP

Obama, left, and first lady Michelle Obama, right, tango with dancers during a state dinner in Buenos Aires on March 23, 2016. Pablo Martinez Monsivais/AP

The Obamas read a book to children at the annual White House Easter Egg Roll on March 28, 2016. The Easter Egg Roll has been a White House tradition since 1878, when President Rutherford B. Hayes allowed children to roll eggs on the South Lawn. Olivier Douliery/Getty Images

Obama and his daughter Malia walk down the steps of Air Force One after arriving in Chicago on April 7, 2016. She will be attending Harvard University after taking a gap year, the White House announced in May. MANDEL NGAN/AFP/Getty Images

Obama talks with Britain's Prince William, right, as William's wife Catherine, the Duchess of Cambridge, plays with their son, Prince George, on April 22, 2016. The President and his wife were visiting Kensington Palace in London. Kensington Palace/Getty Images

Obama tests virtual-reality goggles during a trade fair in Hanover, Germany, on April 25, 2016. Carolyn Kaster/AP

Obama and Japanese Prime Minister Shinzo Abe shake hands after laying wreaths at the Hiroshima Peace Memorial Park in Hiroshima, Japan, on May 27, 2016. Obama, the first sitting U.S. President to visit Hiroshima, called for a "world without nuclear weapons" during his speech. Carolyn Kaster/AP

The President arrives in the White House briefing room to deliver remarks on June 23, 2016. The Supreme Court had announced that day that it was evenly divided in a case concerning Obama's executive actions on immigration reform. STEPHEN CROWLEY/The New York Times/Redux

Obama hugs his daughter Malia at the White House Fourth of July party in 2016. She was celebrating her 18th birthday during the party, which included musicians Janelle Monae and Kendrick Lamar. Aude Guerrucci/Getty Images

The Obamas sit next to former U.S. President George W. Bush at a memorial service in Dallas for the five police officers who were killed during a protest on July 7, 2016. Obama said that the nation mourned along with Dallas, but he implored Americans not to give in to despair or the fear that "the center might not hold." STEPHEN CROWLEY/The New York Times/Redux

Obama hugs Hillary Clinton after speaking at the Democratic National Convention on July 27, 2016. "I can say with confidence there has never been a man or a woman -- not me, not Bill, nobody -- more qualified than Hillary Clinton to serve as president of the United States of America," Obama said. David Paul Morris/Bloomberg/Getty Images

Russian President Vladimir Putin meets Obama at the G-20 Summit in Hangzhou, China, on September 5, 2016. Obama, who had a 90-minute session with Putin, said their talk was "candid, blunt and businesslike," and included the issues of cyberintrusions and the Syrian conflict. ALEXEI DRUZHININ/AFP/Getty Images

Obama shakes hands with President-elect Donald Trump in the Oval Office on November 10, 2016. "My No. 1 priority in the next two months is to try to facilitate a transition that ensures our President-elect is successful," Obama said after meeting with Trump for about 90 minutes. Pablo Martinez Monsivais/AP