Begun in 1939, the Manhattan Project eventually employed more than 130,000 people, including our foremost scientists and thinkers, and cost nearly $2 billion, while operating under a shroud of absolute secrecy. This groundbreaking collection of documents, essays, articles, and excerpts from histories, biographies, plays, novels, letters, and the oral histories of key eyewitnesses provides unique perspectives for the historian and student of history all compiled by experts at the Atomic Heritage Foundation. Photographs throughout depict key moments and pivotal figures. The Manhattan Project gives actual voice to a significant period in history.