Based on Howard Zinn's book A People's History Of The United States, the two-hour film chronicles key developments in the US told from the perspective of famous figures and lesser known people like abolitionist Sojourner Truth and anti-war activist Helen Keller.
Mortensen and a host of stars including Danny Glover, Marisa Tomei and Kerry Washington recorded a series of live readings from journals and diaries in Boston last month.
'Our goal is to tell stories about how democracy starts with the people and it's the people's job to force the government and its agencies to live up to the standards that the country was founded on,' executive producer Chris Moore said.
Damon, Dan Fireman, Ara Katz, Art Spigel and Carolyn Mugar are producing and Moore serves as executive producer with Howard Zinn and Anthony Arnove.
John Sloss of Cinetic Media is representing domestic rights.