The famously Democratic actor-director teamed up with an unlikely partner, Cindy McCain, wife of Republican Senator John McCain.
While testifying before a House subcommittee, Affleck said the unrest in eastern Congo includes sexual violence against women and forcing children to fight as soldiers. He called on Washington to help end the suffering of the Congolese people.
"The U.S. is not focused on Congo, even with events like last week's attack on the president's residence in Kinshasa," Affleck testified. "We strongly believe that if we continue to place Congo on the back burner of U.S. policy, it will indeed come back to haunt us. The federal budget may be a zero-sum game, but our morality, our sense of decency, our compassion for our fellow human beings is not."
The Democratic Republic of the Congo is Africa's third largest country, home to more than 68 million people. Since 1998, violence, disease and poverty have killed over 5 million people there and 1.3 million people have been forced from their homes.
In January, Affleck and McCain traveled to the Congo together and saw firsthand how some simple steps can change lives there.
McCain said she was skeptical at first, that it seemed like another cry for attention from another issue-oriented denizen of Hollywood. But Affleck persuaded her of his commitment and a passion that came out on Capitol Hill.
"I will never give in to the naysayers who say Congo is too complex or hopeless. It is not," said Affleck.
He called on the Obama administration to appoint an envoy to Congo to bring order and money to a nation with little of either.
Affleck founded his non-profit Eastern Congo Initiative last year. He also visited the country in 2008 and made a short film about his experiences there.