The first black president has often been surprisingly late-to-the-debate when it comes to talking about race.

Usually when President Obama decides to wade into the divisive issue, he does so carefully and deliberately with the knowledge that his comments carry the full weight of the White House and can often make tricky situations more difficult.

His careful remarks on the unrest in Ferguson, Mo., were no exception. They marked one of a handful of times that President Obama has openly addressed America's racial divide while in office.

After the fourth night of clashes between police and protesters over the killing of Brown, an unarmed teenager, by an unnamed policeman in a St. Louis suburb, Obama called the incident "disturbing" before making an appeal for calm.

"We lost a young man, Michael Brown, in heartbreaking and tragic circumstances," Obama said during a break from his vacation on Martha's Vineyard, Mass. "He was 18 years old and his family will never hold Michael in their arms again."

“Now is the time for healing. Now is the time for peace and calm on the streets of Ferguson,” he added, stressing the need for “an open and transparent” investigation “to see that justice is done.”

Although he addressed the issue of race in two high-profile speeches during the 2008 campaign, Obama was more circumspect as president. His most extensive comments on the subject in office weren't until 2012, when the slaying of Trayvon Martin by neighborhood watch volunteer George Zimmerman in Florida led to a national debate.

In an unscheduled appearance before reporters at the White House, Obama talked about Martin’s shooting death.

“Trayvon Martin could have been me 35 years ago,” he said, adding that the nation needed to look for ways to move forward after the shooting and urged Americans to do some soul searching about their own attitudes on race.

For many in the black community, it was just the kind of frank talk they expected about what it's like to be black in America from the first black president. But critics took exception to the president weighing in to sympathize with one side without knowing all the facts in a case they believed should be left to the courts to decide.

Other times Obama has commented on explosive racial clashes only when asked.

Back in 2009, responding to the final question of a prime-time news conference, Obama said police in Cambridge, Mass., acted “stupidly” when they arrested Harvard University professor Henry Louis Gates, Jr. in his own home.

He went on to talk about the prevalence of police racial profiling in the country – of “African-Americans and Latinos being stopped by law enforcement disproportionately.”

“That’s just a fact,” he said.

He quickly tempered the comments by saying that the police at first acted appropriately in responding to a call that a man was seen forcibly entering the Gates home.

He and Vice President Joe Biden later tried to smooth things over with a lighthearted “beer summit” between Gates and police Sergeant James Crowley, who mistakenly arrested him then later dropped the charges.

Before the Ferguson comments Thursday, Obama most recently spoke about race in a carefully packaged New Yorker profile by David Remnick.

“There’s no doubt that there’s some folks who just really dislike me because they don’t like the idea of a black president,” he said during one of his many interviews with Remnick over the last few months.

“Now the flip side of it is there are some black folks and maybe some white folks who really like me and give me the benefit of the doubt precisely because I’m a black president,” he added.