President Obama on Tuesday awarded the nation’s highest civilian honor to 17 Americans, including Hollywood stars, a prominent Republican environmentalist, two baseball legends and several civil rights pioneers.

Obama reveled in the stories about the Presidential Medal of Freedom honorees — some of the country’s most famous celebrities as well as lesser-known social agitators. “What an incredible tapestry this nation is,” he said. “And what a great blessing to be in a nation where individuals as diverse, from as wildly different backgrounds, can help to shape our dreams, how we live together, help define justice and freedom and love.”

This year’s recipients included the longest-serving woman in Congress, Sen. Barbara A. Mikulski (D-Md.); famed composer Stephen Sondheim; filmmaker Steven Spielberg; violinist Itzhak Perlman; and Bonnie Carroll, who provides services for military families who have lost relatives who’ve served. The oldest was 97-year-old Katherine G. Johnson, a mathematician who helped chart the first NASA spaceflight. Several honorees — American Indian rights activist Billy Frank Jr., former congresswoman Shirley Chisholm (D-N.Y.), Japanese American activist Minoru Yasui and New York Yankees great Yogi Berra — received the award posthumously.

While the general categories for the Medal of Freedom have remained fairly constant since President John F. Kennedy established the modern version of the award in 1963 — public servants, creative artists and athletes are traditionally well represented — the specific choices often pose a study in contrasts.

Obama has frequently honored civil and human rights activists, people he described Tuesday as “those who have challenged us to live up to our values.” He noted with approval that Frank, who fought for tribes to retain their traditional salmon fishing rights, offered this self-description when he was alive: “I wasn’t a policy guy. I was a getting-arrested guy.”

He lauded New York and San Francisco Giants great Willie Mays as a pioneer for African Americans. “It’s because of giants like Willie that someone like me could even think about running for president,” Obama said.

Some of Obama’s remarks were earnest: He praised former Environmental Protection Agency administrator William D. Ruckelshaus as someone who counted dead fish in Indiana’s streams as “all part of protecting America from big polluters.” But there was also some teasing. He introduced singer Barbra Streisand as “born in Brooklyn, to a middle-class Jewish family,” and then he interrupted himself: “I didn’t know you were Jewish, Barbra.” The audience erupted in laughter.

Obama peppered his comments about folk singer James Taylor with direct quotes from his catchiest tunes, including “You’ve Got a Friend.” He chided the audience for not instantly catching a couple of Berra’s “Yogisms,” such as “If you can’t imitate him, don’t copy him.”

“It took everybody a while,” he said after the delayed laughter.

Also honored were Latin music stars Emilio and Gloria Estefan, and former congressman Lee Hamilton (D-Ind.).

There are clear demographic differences between the recipients Obama has chosen and those George W. Bush picked during his time in office. African Americans represented roughly the same portion of each man’s designations — 18 percent of Obama’s, compared to 17 percent for Bush — but women have made up 36 percent of the medal’s recipients under the current president vs. 15 percent during his predecessor’s tenure. In a similar vein, Obama has awarded the honor to a higher proportion of Hispanics, Asian Americans, Native Americans, and gay and lesbian Americans than Bush.

Obama has awarded 97 medals so far, compared with Bush’s total of 81 and President Bill Clinton’s 88. White House senior adviser Valerie Jarrett said the administration makes no apologies for the longer list under Obama. “There are people he’s had on his mind since he took office,” she said. “He wants to make sure he gives them this honor before he leaves office.”

Philip Bump contributed to this report.