On August 10, 1957 — Mickey Mantle becomes the first player to clear the center field-hedge at Memorial Stadium with his 460-foot homer in the Yankees’ 6-3 victory over the Orioles. Baltimore’s Boog Powell (1962) and Twins’ slugger Harmon Killebrew (1964) will also accomplish the feat.

Source:
Baseball Reference August 10
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game