"It's an amazing confluence of history to have President Obama's inauguration and Dr. King's holiday on the same day," said Seth Andrew, superintendent and founder of the charter school Democracy Prep, which sponsored the celebration.
The kids and parents watched the inauguration and then listened to song and dance performances. Afterward, they performed service such as letter writing, visiting a senior home and cleaning a local park. Police Commissioner Ray Kelly and Assemblyman Keith Wright visited the gathering.
"It's an awesome setting," said Robin Boswell, a legal secretary who came with her daughter Jianna, 12, a Democracy Prep student. "It teaches your kids to activate their skills and put them to use in the world."
Jianna said she was also excited to attend the event.
"I'm excited President Obama was re-elected," she said. "He's intelligent and a great speaker."
Jimena Lezama brought her four children to see the inauguration on the two giant screens set up in the armory.
"He has feelings like a regular person," Lezama said of Obama.
"I think he's a good president," added her daughter, Janet, 12.
When Beyoncé finished singing the national anthem, the crowd roared.
"We want our students to live a life of active citizenship," said Andrew. "And we hope they remember where they were when President Obama was sworn in for a second term."
More than 50 people left the armory and headed over to Harlem River Park to pick up trash as a part of the King Day of Service.
Friends Josephine Miranda and Alexis Davis, both 14-year-old ninth-graders at Democracy Prep, said they felt it was important to perform service Monday.
"If you look around, people of all races are out here coming together for a good cause," said Josephine. "That's what Dr. King was fighting for."
"Barack Obama is living out Dr. King's dream," she said. "We have to encourage people to come together and work out their differences."