First published in 1994 in the NASA Mograph in Aerospace History series. From the introduction: On 25 May 1961 President John F. Kennedy anunced to the nation a goal of sending an American safely to the Moon before the end of the decade. This decision involved much study and review prior to making it public, and tremendous expenditure and effort to make it a reality by 1969. Only the building of the Panama Canal rivaled the Apollo program's size as the largest n- military techlogical endeavor ever undertaken by the United States; only the Manhattan Project was comparable in a wartime setting. The human spaceflight imperative was a direct outgrowth of it; Projects Mercury (at least in its latter stages), Gemini, and Apollo were each designed to execute it. It was finally successfully accomplished on 20 July 1969, when Apollo 11's astronaut Neil Armstrong left the Lunar Module and set foot on the surface of the Moon. Illustrated.