He was the last judicial appointee from the Kennedy administration remaining on the federal bench and among the longest-serving federal judges in history, with over 26 years of active service and nearly 56 years of total service.

Born on July 31, 1923,[1] in Scranton, Pennsylvania, Nealon was a First Lieutenant in the United States Marine Corps during World War II, from 1942 to 1945.

[2] On December 13, 1962, Nealon received a recess appointment from President John F. Kennedy to a seat on the United States District Court for the Middle District of Pennsylvania vacated by John W. Murphy.

He served as Chief Judge from 1976 to 1989, assuming senior status on January 1, 1989,[2] and died on August 30, 2018, in Scranton.

[3] The William J. Nealon Federal Building and United States Courthouse, located in Scranton, is named in his honor.