DONALD Trump was sworn in as US President one year ago today, bringing to an end Barack Obama's eight years in office.

He signed the formal documents at the US Capitol minutes after vowing to give “power to the people”, “put only America first” and “eradicate Islamic terrorism from the face of the earth" in his inaugural address.

3 Donald Trump gives his first speech as US President at his inauguration Credit: Reuters

When was Trump's inauguration?

Donald Trump took to the stage on January 20, 2017, when he was sworn in on the steps of the US Capitol.

The Republican nominee achieved one of the most improbable political victories in modern US history - despite a series of controversies that would easily have destroyed other candidacies, including 'locker room banter' about sexual assault, mocking a reporter with disabilities, inciting his supporters to violence and allegations that his campaign pandered to the American far-right.

He pledged to unite America after his shock election win and had to start putting his promises into policies.

In his last speech as president, Obama said: "The peaceful transfer of power from one freely elected president to the next, I committed to President-elect Trump my administration would ensure the smoothest transition, just as President Bush did for me."

Presidents have been inaugurated on January 20, since Franklin D. Roosevelt took the oath of office in 1937, moving up from the previous day of March 4.

Traditionally Trump spend the morning at a worship service before being handed the nuclear codes and briefed on firing missiles ahead of the ceremony.

The Vice President Mike Pence was sworn in first – then it was Trump's turn.

He took the traditional oath: "I do solemnly swear (or affirm) that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."

Trump was sworn in using two Bibles – his own, and the one used by Abraham Lincoln at his first inauguration in 1861, and the oath will be administered by Chief Justice John Roberts.

The Lincoln Bible is bound in burgundy velvet, and was also used for Barack Obama's inaugurations in 2009 and 2013.

3 Melania and Donald Trump on the way to church on inauguration day Credit: AP:Associated Press

What did Donald Trump say in his inauguration speech?

In front of a crowd of 900,000 Americans, Trump took to the stage and vowed to unite a divided country in his inaugural address.

Trump said: "When America is united, America is totally unstoppable."

He added: "Whether we are black or brown or white, we all bleed the same red blood of patriots.

"A new national pride will stir our souls, lift our sights, and heal our divisions."

Continuing the theme of uniting the country under the American flag, his speech was a patriotic clarion call.

"From this day forward it's going to be only America first...we must think big and dream even bigger. A nation is only living as long as it is striving," he said.

With the eyes of the world on him, as well as famous faces and former presidents in the packed crowd, Trump also used his platform to blast the establishment.

He said: “Today will be remembered as the day the people became the rulers of this nation again.

"We are transferring power from Washington and giving it back to you, the people."

3 Trump formally 'signed in' as US President Credit: Sky News

The highlights from Donald's inauguration speech "You will never be ignored again."

"We will follow two simple rules: Buy American and hire American."

"From this day forward it's going to be only America first."

"We must think big and dream even bigger. A nation is only living as long as it is striving."

“When America is united, America is totally unstoppable."

"Together, we will make America great again."

"January 20th, 2017 will be remembered as the day the people became the rulers of this nation again."

"The time for talk is over, now begins the hour of action."

“We will make America safe again. We will make America great again."

"Whether we are black or brown or white, we all bleed the same red blood of patriots."

"A new national pride will stir our souls, lift our sights, and heal our divisions."

"This moment is your moment. It belongs to you..."

"When your heart is filled with patriotism, there is no room for prejudice."

"I will fight for you with every breath in my body and I will never, ever let you down."

"Don't allow anyone to tell you it cannot be done."

"We must think big and dream even bigger."

What did Obama do on Inauguration Day?

Obama had five things to do on the day before handing over to Trump.

Issue pardons. One of the most controversial pardons was issued by President Gerald Ford TO predecessor Richard Nixon - who had just stepped down after the Watergate scandal. Welcome the Incoming President George and Laura Bush hosted the Obamas for coffee at the White House before the ceremony. Leave a note for the new President Bush's note to Obama wished the new leader well on the "fabulous new chapter" he was about to begin. Attend the Inauguration President Obama attended Trump's swearing-in and inauguration, before being escorted from the Capitol by their successors, Donald and Melania. Helicopter out of Washington This has happened at every ceremony since Gerald Ford's in 1977.