John F. McMullin was an Americanprofessional baseball player. During the first professional league season in 1871, he was the only regular left-hand pitcher, without much success; otherwise he was an emergency pitcher who played outfield and everywhere. After playing almost every game throughout the five National Association seasons, 1871-1875, he did not play a single game in the National League that succeeded it. He died in his native Philadelphia five years later, only 32 years old. In 1867 the 19-year-old McMullin was one regular outfielder for the Keystone club of Philadelphia in the nominally amateur National Association of Base Ball Players. Keystone fielded Philadelphia's second team by playing strength, behind the Athletics. Half the team scored more than three runs per game, including McMullin with 47 in 13 games now on record. For the 1868 season, two Cincinnati clubs both acquired four or five players from the east; presumably they were compensated somehow. John McMullin joined the Buckeyes and played catcher more than anywhere else. Evidently the second-best team in the west, they proved to be fatally second-best in the city behind the Cincinnati Red Stockings and they did not survive to contest the first openly professional pennant race next season. McMullin returned to his native city, now to be catcher, pitcher, and shortstop for the supreme Athletics. He played 49 of 53 known games, the leading number, and held his own in the powerful lineup. For the 1870 season at age 22, McMullin became a regular pitcher for the Haymakers of Troy, New York, a pro team of average strength: another powerful lineup but not much pitching. After Troy helped establish the first professional league in 1871, he continued for a second season in that role. McMullin was the only regular left-hand pitcher in the 1871 National Association but there was at least one other regular lefty pitcher on the professional teams of 1870: Charlie Pabor for the Union of Morrisania.