Burmese opposition leader Aung San Suu Kyi has finally received in person the US Congressional Gold Medal she was awarded under house arrest in 2008.
Aung San Suu Kyi described it as "one of the most moving days of my life".
She also met President Obama at the White House, shortly after the US Treasury said it had lifted sanctions on Burma's President Thein Sein.
Sanctions on Burma have been loosened since the new government began enacting democratic reforms in 2011.
US Secretary of State Hillary Clinton and former first lady Laura Bush were present at the medal ceremony, in the Capitol Rotunda, in Washington.
"The ties of friendship and understanding that have developed between you and lovers of democracy in Burma compensate for much of the trials we had to suffer over the past decades," Aung San Suu Kyi said after receiving the medal.
She said that, despite its inherent imperfections, democracy remained a "beacon of hope for all of us" and reminded the audience that there were many, in Burma and beyond, for whom freedom was "just a dream".
"There will be difficulties in the way ahead, but I'm confident that we shall be able to overcome all obstacles with the help and support of our friends," she added.
Aung San Suu Kyi herself was released from house arrest in 2010.
The BBC's Zoe Conway in Washington says that although the US Congress is rarely a place of unity, in the presence of Aung San Suu Kyi both Democrats and Republicans paid tribute to her achievements.
Mitch McConnell, minority Republican leader, described the event as a "truly special day here at the Capitol".
"It's been a long time coming," he said. "We are honoured to have this hero with us and delighted to award her our nation's highest civilian honour."
Addressing the Burmese opposition leader, US Secretary of State Hillary Clinton said: "It's almost too delicious to believe, my friends, that you are here in the rotunda of our great Capitol, the centrepiece of our democracy, as an elected member of your parliament."
Ms Suu Kyi met with President Barack Obama privately at the White House later on Wednesday. No details were released of their discussion, but reporters said it appeared to be relaxed and informal.
Ahead of the meeting, White House spokesman Jay Carney said the visit provided "another opportunity to reaffirm our long-standing support for her struggle and the struggle of many others toward democratic, just and transparent governance in Burma".
On Tuesday, after a meeting with Secretary of State Hillary Clinton, Aung San Suu Kyi said she supported further easing of sanctions against Burma's military-backed government.
The US Treasury said on Wednesday that Thein Sein and the Speaker of Burma's lower house, Thura Shwe Mann, had been removed from its list of "Specially Designated Nationals" which sanctions individuals.
President Thein Sein himself is expected to visit the US next week when he attends the United Nations General Assembly in New York.
The EU, Australia and other countries have already eased sanctions against Burma.
In July, Mr Obama said that US companies would be allowed to "responsibly do business in Burma".
Thein Sein has urged Western countries to scrap all sanctions against his country.
On Monday state television in Burma reported that more than 500 prisoners, including at least 80 political prisoners, had been granted amnesty.