On June 3, 1965, 120 miles above the Earth, Major Edward H. White
II opened the hatch of the Gemini 4 and stepped out of the capsule, becoming the first American astronaut to walk in space (above). He
was attached to the craft by a 25-foot tether and controlling his movements with  a hand-held oxygen jet-propulsion gun, White
remained outside the capsule for just over 20 minutes. As a space
walker,
White had been preceded by Soviet cosmonaut Aleksei A. Leonov,
who on March 18, 1965, was the first man ever to walk in space.

Edward Higgins White II
(November 14, 1930 – January 27, 1967)

White died on January 27, 1967, alongside astronauts Virgil “Gus” Grissom and Roger B. Chaffee in a fire during pre-launch testing
for Apollo 1 at Cape Canaveral, Florida. He was awarded the
NASA Distinguished Service Medal for his flight in Gemini 4
and posthumously awarded the Congressional Space Medal of
Honor