During World War II, he served in the United States Army, reaching the rank of corporal.

In November 1974, he was re-elected, but he resigned his seat upon appointment to the New York Supreme Court.

[2] In November 1976, he was elected to a 14-year term on the Supreme Court, remaining on the bench until the end of 1990.

On September 18, 1991, he was appointed as a Judge of the Buffalo City Court, to fill the vacancy caused by the resignation of Alois Mazur, and remained on the bench until the end of the year.

[5] McGowan died on July 23, 1997, in the veterans unit of Genesee Memorial Hospital in Batavia, New York.