Calais Campbell is serious about giving back.

Not only has the Arizona Cardinals defensive end started his own non-profit, the Charles Richard Campbell Foundation, he is very active in the NFL's partnership with The United Way.

In fact, while he was in Washington, D.C., attending President Obama's Inauguration, Campbell took time out of his busy schedule to volunteer at Kelly Miller Middle School.

On Jan. 19, a day designated by President Obama as the National Day of Service, Campbell spent the morning painting, cleaning and talking with middle schoolers.

"We spoke to the kids that were there for Saturday school trying to get ahead," Campbell told ThePostGame. "It was an awesome experience."

Campbell was extremely busy for the rest of the weekend, attending the Inauguration, the Inaugural Ball and an Inauguration event for the Athletes and Artists Alliance.

After spending so much of his time in and around the professional sports realm, Campbell said he enjoyed mingling with some of Washington's bigwigs.

"It was cool to meet some of the different people in politics," Campbell said. "That's a field I haven't really experienced. They've got a different way of looking at things and a different way of carrying themselves."

Campbell, who supported Obama in the recent election, was joined over the weekend by his mother and his sister, making the experience all the more memorable.

"It was cool to be with my family," Campbell said. "Having a good time and celebrating something for the nation."

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