Malia, 14 and Sasha, 10 joined their father on stage after he gave a rousing speech to a thunderous applause and cheer from the audience at the convention in Charlotte, North Carolina.
The two girls brought back memories from four years ago for America and the rest of the world when they had walked on stage in Chicago on election night, holding their parents' hands.
Dressed in frocks, the girls appeared both shy and excited as they walked into the national spotlight. Malia and Sasha, wearing chic dresses, appeared more confident and composed at the DNC's closing night yesterday.
Joined by their mother Michelle Obama, the two tall and graceful young women walked up to hug their father and waved out to thousands of his supporters at the convention.
The Obama girls have not made many public appearances in this year's election campaign so far. Their parents have fiercely protected their privacies and are known to have never compromised on the school schedules of the girls.
"Malia and Sasha, you make me so proud....But don't get any ideas, you're still going to class tomorrow," Obama said as he began his acceptance speech.
In the last four years, America has hardly heard the first children speak.
The country has seen the girls grow only through photographs released by the White House from time to time, in campaign videos and through stories and anecdotes told by their parents at public gatherings and interviews.
A lot has changed for the two young girls since they were thrust into the national spotlight in 2008, Malia is now nearly as tall as her parents and is a varsity tennis player.
Sasha, who will enter her teens in the next two years, can speak in Mandarin, a report in the New York Times said.
In her address to the convention on Tuesday, Michelle Obama gave an insight into the life of the First Family when she said her husband sits with their girls at the end of the day, "strategising about middle school friendships."
The report said if the "Obama girls are bit players in the presidential race, they are also important ones, not as campaigners but as characters, highlighting traits important to their father's re-election hopes: his likability and his family-man image.
