William Henry O’Kelleher Jr. (he would later Americanize the name to Keeler) was born in Brooklyn, New York on March 3, 1872. His father, William O’Kelleher Sr., worked as a trolley switch man. Willie Keeler began playing baseball at a young age, and was so good that he was named captain of his high school team as a freshman. His high school career was short-lived, however, as he quit school the following year and went on to play semiprofessional baseball in the New York City area.

After a couple of seasons with the Plainfield Crescent Cities of the Central New Jersey League, Keeler joined the minor league team in Binghamton, New York. He was called up to the New York Giants at the end of the season at the age of 20 years old. Standing only 5-foot-4 and weighing a mere 140 pounds, Keeler was one of the smallest players ever in major league baseball, earning him the nickname “Wee Willie.” Despite his stature, Keeler would establish himself as one of the greatest contact hitters of all time, being notoriously difficult to strike out. His motto at the plate was, “Keep your eye on the ball and hit ‘em where they ain’t.”

Keeler compiled a .341 career batting average, hitting over .300 sixteen times in nineteen seasons, and he hit over .400 once. His best season came in 1897 with the Orioles, when he hit .424 and led the National League with 239 hits in only 129 games. Keeler also started the season with a 44-game hitting streak, beating the previous record of 42. His new mark stood for 44 years before being broken by Joe DiMaggio in 1941.

Keeler twice led his league in batting average and three times in hits. He hit an astounding 206 singles during the 1898 season, a record that stood for more than 100 years. Additionally, Keeler had an on-base percentage of greater than .400 for seven straight seasons, and when Keeler retired in 1910, he was third all-time in hits with 2,932, behind only Cap Anson and Jake Beckley.

Keeler was also a force on the base paths, totaling 495 career stolen bases. Of his 33 career long balls, 30 of them were inside-the-park home runs.

Keeler passed away on January 1, 1923 at the age of 50. He was elected to the Hall of Fame in 1939.