The Braves franchise record for home runs by a rookie is 38 by Wally Berger in 1930.
The MLB National League rookie home run record is jointly held by Wally Berger, who knocked 38 out of the park in his first season with the Boston Braves in 1930, and by Frank Robinson, who matched that feat in his debut with the Cincinatti Reds in 1956. Berger was 25 when he set the mark, older than the average rookie. Robinson was 21.
The AL rookie home run record is held by Mark McGwire who hit 49 home runs for the Oakland Athletics in 1987.
In 1987, Mark McGwire broke the rookie record when he hit 49 home runs for the Oakland A's. His record still stands today.
Cal Ripken Jr. holds the Oriole Home Run record with 18 in 1982, also earning him the AL Rookie Of The Year Award.
Most likely Billy Williams, who hit 25 home run in his rookie season in 1961.
49- Mark McGwire
In Game 1 of the 1996 World Series, rookie Andruw Jones of the Atlanta Braves hit home runs in his first two at bats.
The most home runs by a rookie in a season was 49. They were hit by Mark McGwire in 1987. He later broke Babe Ruth's record for a season.