“Quite frankly I was surprised that it had an impact on him. I've known Jason a long time, he didn't need any help in this. He's a thoughtful guy, he's a deliberative guy. He did this all on his own,” Kennedy told WHDH-TV.

With his announcement, Collins became the first active athlete in one of the four major North American sports leagues to announce he was gay. In the Sports Illustrated essay Collins wrote to make his announcement, the former Boston Celtic said that the congressman had partially inspired him.

"I realized I needed to go public when Joe Kennedy, my old roommate at Stanford told me he had just marched in Boston’s 2012 Gay Pride Parade. I'm seldom jealous of others, but hearing what Joe had done filled me with envy," Collins wrote.

Kennedy said that he was "extraordinarily proud" of Collins becoming the first openly gay pro athlete in the NBA.

"He's now a historic figure in sports, he's a historic figure in his country. He's not going let any sort of labels define him," Kennedy said.

The Massachusetts congressman also said Collins had accepted an offer to join him marching in this year's pride parade.

President Obama also telephoned Collins to express support after the NBA player's announcement.

"He seems like a terrific young man. And I told him I couldn’t be prouder of him," Obama told reporters at a press conference Tuesday. "One of the extraordinary measures of progress that we’ve seen in this country has been the recognition that the LGBT community deserves full equality — not just partial equality, not just tolerance, but a recognition that they're fully a part of the American family."