Hank Leiber joined the major leagues at age 22 with the old New York Giants at the height of the Great Depression in 1933 and helped the Giants win back-to-back NL pennants, 1936-1937. An excellent all-around athlete, the 6 ft 1.5 inch, 205 pound Hank Leiber was a three-time All-Star outfielder, and hit over .300 three times, including a career best .331 in 1935. Henry Leiber stats for 1935 include 37 doubles, 4 triples, 22 home runs, 110 Runs, 107 RBIs, 203 hits in 613 at bats in a then 154 regular schedule season. And, he struck out just 29 times while walking 48 times, and posted 314 total bases.

On August 18 1935 he lined 4 extra base hits in a game and a week later powered 2 homers in one inning. In the 1936 World Series against the Yankees with Hall of Famers Lou Gehrig, Joe DiMaggio, Tony Lazzeri and H of F pitchers Lefty Gomez and Red Ruffing the Giants lost in 6 games, Henry Leiber was 0 for 6 at-bats. In the 1937 World Series against the same Yankees, Hank Leiber rose to the occasion and lined 4 singles in 11 at bats, a torrid .364 average, scored twice and had 2 RBIs. In Game 4 Hank Leiber got two hits in a 6-run Giants second inning, and the Giants won that game 7-3. But lost the Series in 5 games. Traded to the Chicago Cubs in December of 1938 Henry Leiber continued powering the ball the next two seasons. In 1939 he hit 3 homers in three straight at bats for the Cubs.