McKinley was initially a student in the George Barr Umprie School held at Whittington Park in Hot Springs, Arkansas and operated by major league umpire George Barr. Before training as an umpire, McKinley had worked as a meatcutter and he was a catcher in semipro baseball. He tried out twice at major league camps and entered umpiring when the tryouts were unsuccessful. His umpiring career began in 1939 in the Ohio State League, where he was paid $100 per month and had to cover his own expenses. He also worked in the North Carolina State League, Michigan State League and American Association. He served in the military between 1943 and 1945. Upon his promotion to Major League Baseball in 1946, McKinley became the first MLB umpire with formal training at an umpire school. McKinley appeared in the World Series in 1950, 1952, 1957 and 1964. He worked the All-Star Game in 1953, 1958 and 1962. In a 1955 game, McKinley ejected outfielder Irv Noren, who became the first player on the New York Yankees to be suspended since 1942. Noren was arguing a call from McKinley on the basepaths when he crowded the umpire. McKinley placed his mask in front of his face during the argument, and the outfielder later said that he was struck in the face with the mask. McKinley said that he was simply shielding his face from Noren's spittle. McKinley made a controversial ruling in his final World Series. With Bob Gibson on the mound for the St. Louis Cardinals in the sixth inning of the second game in the 1964 World Series, McKinley ruled that a Gibson pitch hit Joe Pepitone of the New York Yankees. The Cardinals protested that the pitch first struck Pepitone's bat. Later in the inning, the Yankees took the lead and they ultimately won the game by a score of 8—3. However, the Cardinals won the World Series in seven games. In 1965, a mandatory retirement rule forced McKinley to end his umpiring career at the age of 55.
Personal life
In 1960, two men from Washington, DC attempted to extort money from McKinley and fellow umpire Ed Runge using a photo of the two umpires with two women in a motel room. The two Washington men and one of the women were brought before a magistrate on extortion-related charges. In September of that season, at their own requests, Runge and McKinley were granted leaves of absence for the remainder of the season.
