JOSEPH CAVANAUGH replaced Joseph Wagner as an extra man with Engine Company 1 of the Camden Fire Department when Wagner was removed from service on September 8, 1878. He was re-appointed in 1879, and served until the spring of 1882, when he was replaced by James Brown. He was the brother of Camden fire fighter Benjamin Cavanaugh, with whom he served during his time in the Fire Department, and John Cavanaugh, who served briefly in the early 1890s.

Joseph Cavanaugh was born in Camden's South Ward in December of 1851 to Matthew and Elizabeth Cavanaugh. The Cavanaughs had started their family in Canada, where older brother Benjamin Cavanaugh was born in March of 1843. The 1850 Census indicates that the Cavanaughs had relocated to Pennsylvania, where siblings John and Sarah were born, before coming over to New Jersey. Sister Mary Cavanaugh was born in 1849. The 1850 Census shows the family living in Camden's South Ward. Two more children had been born, sons Joseph and Matthew Jr., were born in the early 1850s. The 1860 Census shows the family still living in Camden's South Ward.

When the Civil War came, older brother Benjamin Cavanaugh enlisted in the Union Army in April of 1861, serving with Company G, Fourth Infantry Regiment New Jersey Militia, a three-months service unit. Several men who served with the Fourth Infantry became members of the Camden Fire Department after it was founded in 1869, including William W. Mines, J. Kelly Brown, Henry F. Surault, Edward Mead, William Cox, James M. Lane, William Gleason, Theodore A. Zimmerman, Charles G. Zimmerman, William C. Lee, George B. Anderson, Jesse Chew, William H.H. Clark, Cornelius M. Brown, John J. Brown, Benjamin Connelly, and G. Rudolph Tenner. Several other Fourth Infantry veterans played significant roles in Camden in the ensuing years.

If they hadn't already been involved before going into the Army, Benjamin Cavanaugh and several of his companions became involved in volunteer firefighting in Camden after their return. 

When the census was taken in 1870, Matthew Cavanaugh Sr. had passed away. Mary Cavanaugh had married Christopher Mines Jr., who would go on to a long and distinguished career in Camden politics and government. Mines' brother, William W. Mines, was an Assistant Fire Marshal with the Camden Fire Department, and had served with Benjamin Cavanaugh during the Civil War. He may well have been instrumental in securing Cavanaugh's appointment to the Fire Department. Cavanaugh's widowed mother, Mary Cavanaugh, with her sons John and Matthew, lived with Christopher and Mary Mines, and their 10-month old son, Marcus K. Mines, according to the census sheet, which was taken by J. Kelly Brown, another Civil War comrade AND member of the Camden Fire Department. (Note: As of February 4, 2011, Joseph and Benjamin Cavanaugh's 1870 census records have not been located- PMC).

Camden Fire Department records do not show where Joseph Cavanaugh was living when he was appointed in September of 1878. The 1878-1879 City Directory shows that he was living at 265 Pine Street, the home of his brother-in-law Christopher Mines Jr., as was his brother John and widowed mother Elizabeth. Aside from his work with the Fire Department, Joseph Cavanaugh was employed as a printer throughout his working life. 

When the 1880 Census was taken, John Cavanaugh had moved out of the Mines' home at 265 Pine Street and brother Benjamin Cavanaugh had moved in. The Census shows that Elizabeth Cavanaugh and Joseph Cavanaugh were still living there, and that Joseph Cavanaugh was at that time laid up with a broken leg. 

Joseph Cavanaugh does not appear in the 1881-1882 City Directory. He was working as a printer in Philadelphia an boarding at 522 Spruce Street when the 1882-1883 Directory was compiled. From 1882 through 1888 he lived with his brother Benjamin at 279 Liberty Street. The 1890-1891 Directories show the Cavanaugh brothers at 1012 South 2nd Street. The 1891-1892 Directory states that the Cavanaugh brothers had both "removed to Philadelphia". 

Benjamin Cavanaugh returned to Camden by the time that the 1892-1893 Directory was being compiled. He was living at 815 South 6th Street with a woman named Emma. Joseph Cavanugh appears to have remained in Philadelphia until 1894, as the 1894-1895 City Directory shows him living there as well.

Joseph Cavanaugh does not appear in Camden City Directories again until 1898. He was then living at 106 Kaighn Avenue, still working in Philadelphia as a printer. 

The 1899 City Directory shows Joseph Cavanaugh living with Benjamin and Emma Cavanaugh at 405 Division Street. Both brothers were living at 230 Division Street by the following year. 

Joseph Cavanaugh had himself never married. The 1900 Census has both Joseph and Benjamin Cavanaugh boarding at 230 Division Street, the home of Emma Clare. It is likely that Benjamin had been living with Emma as man and wife for several years prior to the Census, i.e., the Emma in the City Directory and the Emma in the Census were one and the same person. The census made no allowances for unmarried couples, a member of the opposite sex who was living with whomever was the head of household was considered a "boarder" and was assumed to be renting a room there. The 1900 Census states that Benjamin Cavanaugh single. The 1900 Census also shows that Joseph Cavanaugh was still working in the printing industry, by this time as a compositor.

Joseph Cavanaugh died on August 26, 1901. Things did not go well for Benjamin Cavanaugh in the 1900s, either. The 1910 Census shows Benjamin Cavanaugh as an inmate at the Camden County Almshouse in Gloucester Township. Benjamin Cavanaugh did not, however, end his days in the Almshouse. He was making his home at 234 Clinton Street in South Camden when he died in November of 1911 from "paralysis", most likely a stroke. He was buried on November 7, 1911 in the Soldiers Plot at New Camden Cemetery.