O'Rourke was born in East Bridgeport, Connecticut. On April 22, 1876, he had the first base hit in National League history. After leaving the major leagues following the 1893 season he continued to play in the minor leagues until he was over 50 years old. In 1904 he made a final appearance with the New York Giants under manager and friend John McGraw, becoming at age 54 the oldest player ever to appear in the National League, and the oldest player to hit safely in a major league game. He returned to the minors as president of the Connecticut League, and in 1912 returned to the field to catch a complete minor league game at the age of 60.
O'Rourke is one of only 29 players in baseball history to appear in Major League games in four decades.
He graduated from Yale Law School in 1887 with an LL.B., practicing law in Bridgeport between early playing stints, and earning the nickname "Orator Jim" because of his verbosity on the field, his intellect, and his law degree—uncommon in a game regarded as a rough immigrant sport at the time. Legend has it that O'Rourke, a child of Irish immigrants, was asked to drop the "O'" from his last name when he signed a contract with Boston and its Protestant backers, but refused, saying "I would rather die than give up my father's name. A million dollars would not tempt me." As an executive, O'Rourke later hired the first African American minor league baseball player in history.
"O'Rourke has made a brilliant record for himself as an outfielder, being an excellent judge of a ball, a swift runner, and making the most difficult running catches with the utmost ease and certainty. As a thrower, too, he stands pre-eminent, being credited with a throw of 365 feet, the next to the longest yet accomplished by any player."