In 1936, some 2,800 young Americans, together with 50,000 volunteers from 54 countries, offered their lives in defense of the Spanish Republic. What is less known is that 85 African Americans joined that heroic struggle to fight against racism and for the very civil rights denied to them in their own country. This is their story, an untold chapter in the history of both the United States and Spain. The adventures of invisible heroes who answered the call of a distant war to fight for their own freedom.