Former President George W. Bush and his brother, former Florida Gov. Jeb Bush, made a surprise visit to the Capitol Rotunda Tuesday to greet mourners as their father, former President George H.W. Bush, lay in state.

The Bush brothers were accompanied by their wives and the 43rd president's daughters, Jenna and Barbara. They spent about 10 minutes shaking hands and hugging members of the public who were filing past the casket of the 41st president, who died in Houston Friday night at age 94. At one point, George W. Bush even held a baby brought to the Capitol by a mourner.

Earlier in the day, George W. Bush and Laura Bush met with President Trump and first lady Melania Trump for approximately 20 minutes at Blair House, where the Bushes are staying for the elder Bush's state funeral. Other members of the Bush family passed by the former president's coffin during the day, including his son Neil Bush, his brother Jonathan Bush and his nephew Billy Bush, the former host of "Access Hollywood."

Soldiers, star athletes, Cabinet members, citizens in wheelchairs and long lines of ordinary citizens filed through the rotunda all day Tuesday. Some of the visitors recalled key moments in the 41st president's long career of public service. Others focused on his personal life, including his love of sports -- particularly golf and baseball.

Bush was the only CIA director to become president, and former agency directors William Webster, George Tenet and John Brennan joined current Director Gina Haspel in front of the Lincoln Catafalque on Tuesday morning. The agency's headquarters in Langley, Va., was named for Bush in 1999.

The defining moment of Bush's presidency was the operation to drive Iraqi forces from Kuwait in 1991, and retired Gen. Colin Powell -- then the chairman of the Joint Chiefs of Staff -- led a group of Desert Storm leaders into the rotunda. A little more than an hour later, Sheikh Sabah IV Ahmad Al-Jaber Al-Sabah, the Emir of Kuwait who was that country's foreign minister at the time of Saddam Hussein's invasion, paid his respects.

Bush's service dog, Sully, made an appearance in the rotunda accompanied by people who came to commemorate Bush's signing of the Americans with Disabilities Act, the 1990 law that, among its many provisions, required businesses that prohibit pets to give access to service dogs. The 2-year-old yellow Labrador, who had been the former president's constant companion in the final months of his life, achieved worldwide fame after Bush family spokesman Jim McGrath tweeted a photo of the animal lying near Bush's flag-draped casket with the caption, "Mission completed."

Sully was accompanied by Valerie Cramer, America's VetDogs service dog program manager. At her command, he lay down — and threw a glance over his shoulder at the photographers scrambling to get his photo. He didn't seem fazed. Cramer then led him around the casket to sit among the others. After a few minutes, the procession headed out.

Trump visited the Capitol Rotunda on Monday to pay tribute to the 41st president, while Vice President Mike Pence delivered remarks at a Monday ceremony upon the arrival of Bush's casket at the Capitol. Several members of the Trump Cabinet attended the ceremony, while Housing and Urban Development Secretary Ben Carson passed through the rotunda on Tuesday afternoon.

Cindy McCain, the widow of U.S. Sen. John McCain, R-Ariz., who died earlier this year, paid her respects in the Rotunda, where she was accompanied by Senate Majority Leader Mitch McConnell, R-Ky.

Just before 4 p.m., a who's who of professional athletes passed through the rotunda led by CBS Sports broadcaster Jim Nantz, a close friend of the Bush family. They included golfers Jack Nicklaus, Fred Couples, Ben Crenshaw, Hale Irwin, Davis Love III, Phil Mickelson and Greg Norman; tennis stars Chris Evert and Pam Shriver; Duke basketball coach Mike Krzyzewski; former NFL quarterback Peyton Manning; baseball star Albert Pujols and Hall of Fame manager Tony La Russa.

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A state funeral will be held for Bush on Wednesday morning at Washington National Cathedral. Trump will attend, but will not speak. The eulogists announced by the Bush family include George W. Bush, former Sen. Alan Simpson, former Canadian Prime Minister Brian Mulroney and presidential historian and Bush biographer Jon Meacham, who also paid his respects at the rotunda on Tuesday.

Britain's Prince Charles has said that he will attend the state funeral, representing his mother, Queen Elizabeth II. The queen released a statement honoring Bush over the weekend, calling the 41st president "a patriot, serving his country with honor and distinction in office and during the Second World War." Former Polish President Lech Walesa, the founder of the anti-Communist Solidarity movement, and the current Polish president, Andrzej Duda, are planning to attend.

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Walesa on Saturday also credited Bush with a historic role, saying "he did much to overcome communism and help Poland" and that Bush "will remain forever in our hearts and memory."

Fox News' Jodie Curtis and The Associated Press contributed to this report.