04/05/2012 04:35 pm ET Updated Jun 05, 2012

Colin Powell Turns 75 (PHOTOS)

It may be hard to remember now, but there was a time when Colin Powell's name was regularly bandied about as a potential presidential candidate -- and possibly the first black president. He had already tallied a serious of Washington firsts -- he was the first African-American National Security Advisor under Ronald Reagan and the first African-American chairman of the joint chiefs of staff under George H.W. Bush.

Powell, who turns 75 today, was even the frontrunner in an early poll as a challenger to Bill Clinton in 1996, even though he had not declared that he was running. But the Harlem native said he held little interest in electoral politics.

But his career may be defined by his 2003 speech to the United Nations that made the case for war against Iraq. Behind the scenes, Powell had been pushing the Bush Administration to bring other countries into the fold before invading Iraq, and privately expressed doubts. His reputation as a voice of reason and his foreign policy bona fides were a major reason the White House tapped him to make the argument. Powell argued before the U.N. that Iraq was making weapons of mass destruction.

" Indeed, the facts and Iraq's behavior show that Saddam Hussein and his regime are concealing their efforts to produce more weapons of mass destruction."

Much of the information included in that speech was later proven to be false.

After leaving the Bush administration, Powell became a critic of the administration's response to Hurricane Katrina, and later went on to become an occasional sounding board for President Obama, whom he endorsed for president.

"I think that Senator Obama brings a fresh set of eyes, a fresh set of ideas to the table," he said in 2008. "I think we need a generational change, and I think Senator Obama has captured the feelings of the young people of America and is reaching out in a more diverse, inclusive way across our society."

His endorsement was powerful -- even after the Iraq war, three in four Americans had a favorable opinion of him -- and it received days of attention during the last weeks of the campaign.