On 3 June 1965 Gemini IV launched from Cape Canaveral with Jim McDivitt and Ed White on board. One year later (3 June 1966) Gemini IX launched with Tom Stafford and Gene Cernan on board.
Ed White conducted the first American spacewalk during the Gemini IV mission. He was later one of the three astronauts killed during the Apollo 1 fire.
Stafford and Cernan were originally the backup crew for Gemini IX but the primary crew was killed in a plane crash.
McDivitt, Stafford and Cernan all later commanded Apollo missions. McDivitt commanded Apollo 9 which was the first test of the full Apollo craft with the Lunar Module. Stafford commanded Apollo 10 (with Cernan as the LM pilot). Cernan returned to the Moon as commander of Apollo 17.
Image via NASA