WASHINGTON — From the musicians in new purple uniforms who traveled from places like Des Moines and Montgomery, Ala., to march with a gay and lesbian band, to high school mariachi performers from Texas — including some who took their first plane ride to get here — to scores of elegant African-American women in full-length mink coats and matching hats, the faces of Inauguration Day 2013 were the faces of those left behind by the political process in decades and centuries past.

If Jan. 20, 2009, was a day for the history books and a feel-good moment for all of America, Monday was a celebration for the diverse coalition that landed the nation’s first black president in the White House for a second term: Latinos, gay people, women and especially African-Americans.

Riding on a bus to the heated staging tent on the National Mall, members of the Lesbian and Gay Band Association listened intently as the radio played President Obama’s Inaugural Address. A tear streamed down the cheek of Gary Nell, a 53-year-old drum major from Des Moines, as Mr. Obama referred to the Stonewall riots of 1969 in New York, which spawned the gay rights movement. “It was so affirming,” Mr. Nell said.

Outside the security perimeter, 11-year-old Angel Lucero, fresh-faced and earnest, politely asked passers-by where he and his family might get tickets to the swearing-in. His parents, Mexican immigrants, spoke little English. His older sister, Jennifer, 15, said they had come from Bladensburg, Md., to see the president “because we think that he’s going to help us, help other people who aren’t free in this country.”