BOSTON (TheBlaze/AP) — NBA veteran center Jason Collins, the first active athlete in one of the four U.S. major professional sports leagues to come out as being gay, marched Saturday for nearly three miles in Boston’s gay pride parade.

Gay NBA Player Jason Collins Marches in Bostons Gay Pride Parade

NBA veteran Jason Collins, left, marches in Boston’s gay pride parade alongside U.S. Rep. Joe Kennedy III, a college roommate, second right, and Kennedy’s wife Lauren Anne Birchfield, center, Saturday, June 8, 2013, in Boston. Collins is the first active player in one of four major U.S. professional sports leagues to come out as gay. (Credit: AP)

Collins wore a T-shirt that read (hash)BeTrue when he joined thousands of marchers in the parade—including U.S. Rep. Joe Kennedy III, his onetime roommate at Stanford University. Collins chatted with well-wishers, greeted other marchers, and held babies as people came up to him to express their support.

Gay NBA Player Jason Collins Marches in Bostons Gay Pride Parade

NBA veteran Jason Collins, the first active player in one of four major U.S. professional sports leagues to come out as gay, holds 19-month-old Evangeline Salzberg, of Bellingham, Mass., as he walks in Boston’s gay pride parade, Saturday, June 8, 2013, in Boston. (Credit: AP)

The parade also featured former U.S. Rep. Barney Frank – the first sitting member of Congress to enter into a same-sex marriage – who also represented Massachusetts’ 4th Congressional District before Kennedy. U.S. Rep. Ed Markey, the Democratic U.S. Senate candidate seeking the seat once held by John Kerry, who stepped down to become secretary of state, also marched.

In coming out as gay in April, Collins wrote in an article for Sports Illustrated that his decision to go public came when his former roommate Kennedy marched in last year’s parade, and Collins didn’t feel that he could join him.

Gay NBA Player Jason Collins Marches in Bostons Gay Pride Parade

NBA veteran Jason Collins, left, the first active player in one of four major U.S. professional sports leagues to come out as gay, shakes hand with Boston Marathon hero Carlos Arredondo, as they both participated in Boston’s gay pride parade, Saturday, June 8, 2013, in Boston. Looking on is former Congressman Barney Frank, second from left. (Credit: AP)

He also said the Boston Marathon bombing reinforced the notion that things can change in an instant, so he might as well live truthfully.

Collins played for six teams in 12 seasons and becomes a free agent next month. The Celtics dealt him to the Washington Wizards in a midseason trade.

Kennedy said in April that he’s proud to call Collins a friend.

Collins said at the time he “endured years of misery and gone to enormous lengths to live a lie.”