The 'Original Seven'
U.S. astronauts were the seven pilots chosen to train for and perform the manned
Mercury missions, first introduced to the public on April 9, 1959. 508 service records of American military officers were searched, 110 were found to meet pre-established standards, 56 began the testing process, and finally these seven were chosen from the 18 finalists:
- Lieutenant Colonel John Herschel Glenn, Jr., USMC
- Lieutenant Commander Walter Marty Schirra, Jr., USN
- Lieutenant Commander Alan Bartlett Shepard, Jr., USN
- Lieutenant Malcolm Scott Carpenter, USN
- Captain Donald Kent 'Deke' Slayton, USAF
- Captain Leroy Gordon 'Gordo' Cooper, Jr., USAF
- Captain Virgil I. 'Gus' Grissom, USAF
source:
http://www-pao.ksc.nasa.gov/kscpao/history/mercury/mercury-overview.htm