“I am thankful to Professor Gates and Sergeant Crowley for joining me at the White House this evening for a friendly, thoughtful conversation,” Mr. Obama said in a statement. “Even before we sat down for the beer, I learned that the two gentlemen spent some time together listening to one another, which is a testament to them.”

The addition of Mr. Biden was interesting, for a number of reasons. Mr. Biden was able to draw on his credibility with blue-collar, labor union America and his roots in Scranton, Pa., to add balance to the photo op that the White House presented: two black guys, two white guys, sitting around a table.

Earlier in the day, Mr. Obama had berated reporters for obsessing on the theatrics of the meeting, saying he was “fascinated with the fascination” over the issue, which has been boiling since Sergeant Crowley, responding to a call about a possible break-in, arrested Professor Gates for disorderly conduct even though he had ascertained that he was in his own home.

Mr. Obama added fuel to the fire a week later when he said in response to a question at a news conference that the Cambridge police had “acted stupidly” in arresting Professor Gates, a word choice he later said he regretted.

“I noticed this has been called the beer summit,” Mr. Obama said after meeting earlier Thursday with President Gloria Macapagal Arroyo of the Philippines. “It’s a clever term, but this is not a summit, guys. This is three folks having a drink at the end of the day and hopefully giving people an opportunity to listen to each other.”

The press was allowed only a peek at the gathering for about 40 seconds  and from a distance so great that reporters could not hear a word that was said.

Nonetheless, some details emerged:

¶Mr. Obama and Mr. Biden were in shirtsleeves; Sergeant Crowley and Professor Gates wore suits.

¶The four drank out of beer mugs. Mr. Obama had a Bud Lite, Sergeant Crowley had Blue Moon, Professor Gates drank Sam Adams Light and Mr. Biden, who does not drink, had a Buckler nonalcoholic beer. (Mr. Biden put a lime slice in his beer. Sergeant Crowley, for his part, kept with Blue Moon tradition and had a slice of orange in his drink.)