Manuel Balce Ceneta/AP Images

Congress got an unpleasant wake-up call from Hollywood today: Nearly 150 years after President Lincoln issued the Emancipation Proclamation, slavery still persists in the United States of America.

Wearing a white T-shirt that declared "Free Slaves" beneath a brown blazer, actress Jada Pinkett Smith testified before Congress today to draw attention to human trafficking and forced labor, not only in the United States, but around the world.

"This old monster is still with us," Pinkett Smith told the Senate Committee on Foreign Relations. "This is an ugly, and too often invisible, problem."

Various estimates indicate that between 21 million and 27 million people are currently enslaved around the world, including an approximation of 40,000 victims in the United States.

"Fighting slavery doesn't cost a lot of money," she said. "The costs of allowing it to exist in our nation and abroad are much higher. It robs us of the thing we value most - our freedom. We know what that freedom is worth."

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Pinkett Smith said she became interested in the issue after her daughter, Willow, brought to her attention the Kony 2012 YouTube documentary about Ugandan warlord Joseph Kony and African children forced into sexual slavery or used as soldiers.

Pinkett Smith was accompanied on Capitol Hill by her husband, actor Will Smith, and their daughter. She also brought along three trafficking survivors to help underscore the gravity of the issue and press Congress for more action.

"We need more adequate funding for programs that can actually, first, protect young women and men who are victims of trafficking and then also the programs that help transition our young people from those traumas into being able to create and develop lives so that they're not only survivors but they are thriving," Pinkett Smith said. "These young ladies that are here with us today are young women who are not just surviving but they're thriving."

The survivors did not testify, but stood to be acknowledged during the hearing.

"It is so important for people to be able to see real people that this affected and whose lives were turned completely upside down but who have turned their lives back," Sen. John Kerry, the chairman of the committee, said at the hearing. "Until I came to the Senate and began to learn about this [by working on] this committee, I had no idea that these kinds of things were happening right here in our own country."

While Congress has authorized legislation, including the Trafficking Victims Protection Act, multiple times over the past dozen years to combat human trafficking, future funding has yet to be appropriated.

"It's disturbing, obviously, that there are as many people, that it's probably grown, not diminished, even though we've made progress in certain places," Kerry, D-Mass., added. "There has to be a much more concentrated global effort on this."