"He has elevated African-American people so much," Cummings told CNN's Chris Cuomo on "New Day." "And Michelle Obama, as they say, put the O in Obama."
"I cannot tell you how proud I am of them," the Maryland Democrat added.
Cummings said Obama's election gave some of his Baltimore neighbors hope that they previously lacked.
"I look at the guys in my neighborhood. I live in the inner city. They're pressing their chest out a little more," he said. "They used to think the only thing they could become is a basketball player, a football player. Now they know they can become the President of the United States."
Cummings said he could not have imagined that Obama would go from the Senate to the Oval Office.
"He said back then, 'I'm going to win.' But I never dreamed it," he said.
Obama will speak Tuesday from his hometown of Chicago, the city where he declared victory in 2008 and 2012, to give his farewell address.
Cummings said he looks forward to the President sharing his successes.
"I want to hear what the president has talk about what he accomplished. I have seen Republicans torpedo every single thing he has done," he said. "They have stood in his way over and over."
The lawmaker hopes Obama doesn't spend his post-White House years as a spectator but as an influencer.
"We're talking about the future of America and so when he goes out, I don't want him to sit back and lay back and say, 'Okay, I'm going on vacation,'" Cummings said. "I want him to get a little vacation, get rest, but if he sees things going wrong that will affect children yet unborn, I want him to do that."
Senior Adviser Valerie Jarrett also told "New Day" that Obama will spend his post-White House days focusing on the Obama Center.
"He's looking forward to working on the Obama Center," she told CNN's Alisyn Camerota. "He wants it to be more than just a library reflecting on the past and his important time in office, but really a beacon of hope for not just Chicago but the world."