Barack and Michelle Obama have left Capitol Hill after the inauguration of President Donald Trump.
As per tradition, the outgoing president left with little ceremony.
The Handbook of Official and Social Etiquette and Public Ceremonies at Washington, written in 1889, reads: "His departure from the Capital is attended with no ceremony, other than the presence of the members of his late Cabinet and a few officials and personal friends.
"The President leaves the Capital as soon as practicable after the inauguration of his successor."
Donald Trump promised the American people they will "never be ignored again", as he pledged to build a stronger, prouder and safer country.
Concluding his opening address after being sworn in as the country's 45th president, he said: "So to all Americans in every city near and far, small and large, from mountain to mountain, from ocean to ocean, hear these words - you will never be ignored again.
"Your voice, your hopes, and your dreams will define our American destiny and your courage and goodness and love will forever guide us along the way.
"Together, we will make America strong again. We will make America wealthy again. We will make America proud again. We will make America safe again, and yes, together we will make America great again. Thank you. God bless you, and God bless America."
President Donald Trump has taken control of the presidential Twitter account and website.
Within moments of being sworn in, the @POTUS account had been created for the new US leader with the description: "45th President of the United States. Working on behalf of the American people to make our country great again."
Barack Obama's account now has the handle @BarackObama.
Donald Trump has pledged an new "America first" vision for the United States, as he vowed the country will start "winning again like never before".
In his first address to the American people as president, he also promised to protect the country's borders "from the ravages of other countries".
"From this day forward a new vision will govern our land. From this day forward its going to be only America first, America first," he said.
"Every decision on trade, on taxes, on immigration, on foreign affairs will be made to benefit American workers and American families.
"We must protect our borders from the ravages of other countries making our products, stealing our companies and stealing our jobs.
"Protection will lead to great prosperity and strength. I will fight for you with every breath in my body and I will never ever let you down.
"America will start winning again. Winning like never before."
President Donald Trump is still in "campaigning mode", a Washington insider has told ITV News.
The new US President included phrases such as "America first" and "the people are rulers of this nation again" in his inauguration.
He concluded his speech by echoing promises from his campaign: "Together, we will make America strong again.
"Together, we will make America wealthy again.
"Together we will make America proud again.
"Together, we will make America safe again.
"And together, we will make America great again."
Donald Trump has pledged to hand power from Washington to the people, in his opening address as US President.
"Today we are not merely transferring power from one administration to another, or from one party to another, but we are transferring power from Washington DC and giving it back to you - the people," he said.
"For too long, a small group in our nation's capital has reaped the rewards of government while the people have born the cost.
"Washington flourished, but the people did not share in its wealth. Politicians prospered but the jobs left and the factories closed. The establishment protected itself but not the people of this country.
"January 20th 2017 will be remembered as the day the people became the rulers of this nation again."
Donald Trump said the people of America are joined in a "great national effort" to "restore its promise".
Addressing a huge crowd outside the US Capitol building moments after being sworn in as the country's 45th president, he said the country faces "hardships", but insisted: "we will get the job done."
He added: "Together we will determine the course of America and the world for many, many years to come.
Mr Trump also thanked Barack and Michelle Obama, who he said had been "magnificent" in the transition period since last November's election.
Donald Trump has been sworn in as the 45th US President.
Taking the Oath of Office at ceremony on the Capitol West Front, which has been the main site for the occasion since 1981, he said: "I Donald J Trump do solemnly swear, 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."
Mike Pence swears allegiance to the United States as he becomes Donald Trump's Vice President.
Taking the oath with Clarence Thomas, the longest-serving African-American Justice in American history, reading, he pledged: "I do solemnly swear that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God."
Donald Trump mouthed "hello" to the world just moments before his inauguration in a bizarre moment.
Looking deadpan, the President-elect turned to stare straight into a camera, before smirking and mouthing the word "hello" - ahead of taking his seat at the ceremony.