Day One is a made-for-TV documentary-drama movie about The Manhattan Project, the research and development of the atomic bomb during World War II. It is based on the book by Peter Wyden. The movie was written by David W. Rintels and directed by Joseph Sargent. It starred Brian Dennehy as General Leslie Groves, David Strathairn as Dr. J. Robert Oppenheimer and Michael Tucker as Dr. Leo Szilard. It premiered in the United States on March 5, 1989 on the CBS network. It won the 1989 Emmy award for Outstanding Drama/Comedy Special. The movie received critical acclaim for its historical accuracy despite being a drama.