In 1962, John H.Glenn Jr., aboard Friendship 7, became the first American to orbit the Earth.
An Atlas launch vehicle propelled a Mercury spacecraft into Earth orbit and enabled Glenn to circle Earth three times. The flight lasted a total of 4 hours, 55 minutes, and 23 seconds before the Friendship 7 spacecraft splashed down in the ocean. Most major systems worked smoothly, and the flight was a great success as an engineering feat.
Learn more at http://history.nasa.gov/friendship7/