Next Tuesday, April 12, will mark the 50th anniversary of the first human spaceflight. On that date in 1961, Soviet Air Force pilot Yuri Gagarin completed one orbit of the Earth in his Vostok-1 spacecraft. Here is an excellent infographic from SPACE.com that shows how the mission worked:
Source SPACE.com: All about our solar system, outer space and exploration
It would be almost a month later that Alan B. Shepard, Jr., would become the first American astronaut in space with a suborbital flight aboard the Mercury spacecraft Freedom 7. John H. Glenn, Jr., became the first American astronaut to orbit the Earth on February 20, 1962, completing three orbits in his Friendship 7 spacecraft.