The Mercury program was the first human spaceflight program of the United States, running from 1958 to 1963. Its main goal was to send a human into space and return them safely. The program successfully launched six crewed missions, with Alan Shepard becoming the first American in space in 1961. The Apollo program followed, aiming to land humans on the Moon and bring them back safely. It operated from 1961 to 1972 and included notable missions like Apollo 11, where astronauts Neil Armstrong and Buzz Aldrin became the first humans to walk on the lunar surface in 1969.