They arrive from around the world for countless reasons. Many come simply to make a living. Others are fleeing persecution in their native countries. Millions of immigrants risk deportation and imprisonment by living in the U.S. without legal status. They are living underground, with little protection from exploitation at the hands of human smugglers, employers, or law enforcement. Underground America, from the Voice of Witness series, presents the remarkable oral histories of women and men struggling to carve a life for themselves in the U.S.