JOSEPH GENTLESK was born in Philadelphia, Pennsylvania on September 21, 1893 to Felix (Philip) and Mary Gentlesk, who had both been born in Italy. When the Census was taken in 1910 he was the oldest of the six children still living, two having died. The family lived at 134 Stanley Street in South Camden. Felix Gentlesk worked as a laborer, and Joseph was also working as a laborer, at the Howland Croft & Son mill on Broadway at Winslow Street. Besides Joseph, the younger children then at home were Charles, Annie, Nettie, Rocco "Roxie", and Michael. Another son, Daniel,was born in 1912.

When he registered for the draft in June of 1917 Joseph Gentlesk was living at 1029 Locust Street. He was then working as a wagon driver. His mother and brother Charles would still be living at this address as late as 1942. 

Joseph Gentlesk was appointed to the Camden Fire Department on February 17, 1923. He served for over 36 years, retiring on October 1, 1959.

The 1929 Camden City Directory shows Joseph Gentlesk at 260 Mount Vernon Street. Fire Department records from 1931 show Joseph Gentlesk again living at 1029 Locust Street. Census records indicate that although still a city employee, by 1935 Joseph Gentlesk had moved to Haddon Heights, New Jersey. He listed his address at 351 Pine Street, the home of his in-laws, Michael and Rose Burgo.

Joseph Gentlesk passed away on January 3, 1964.