JOHN JOSEPH O'NEIL was born in Camden, New Jersey on August 30, 1909 to Thomas J. & Elizabeth O'Neil. His father worked, according to the 1910 Census, as a "switchboard man" at a "power house", that is to say, he was an electrician. The family was living at 35 Morse Street in East Camden when the census was enumerated. By 1914 they had moved to 136 North 22nd Street.

The 1920 Census shows the O'Neil family, which by that time had added two daughters, Catherine and Mary, living at 136 North 22nd Street. Another daughter, Margaret, was born after the Census was taken. The 1924 City Directory shows the family had moved across the street to 135 North 22nd Street, where they stayed into 1927.

When the census was taken in April of 1930, the Thomas O'Neil family was living at 49 North 22nd Street. John O'Neill was working as a clerk in a factory. He had left school after the 10th grade to go to work. On July 27, 1938 John J. O'Neil was appointed to the Camden Fire Department. The 1940 Camden City Directory shows John O'Neil living with his parents and siblings at 245 North 32nd Street. He married soon after and by 1943 was living at 2930 High Street.

During World War II John J. O'Neil took some time away from the Fire Department to serve his country as a member of the United States Coast Guard. He returned to the Fire Department after the war. The 1947 City Directory shows him living at 404 North 34th Street. By 1956 John J. and Mary O'Neil had moved to 276 North 33rd Street, where he stayed the remainder of his time with the Camden Fire Department. 

John J. O'Neil was promoted to District Chief  on April 1, 1961. After 30 years service to the City and to his country, John J. O'Neil retired on pension on November 1, 1968. Last a resident of Pennsauken, New Jersey, John J. O'Neill passed away December 20, 1882.