BENJAMIN CAVANAUGH replaced Thomas Allibone as an extra man with Engine Company 1 of the Camden Fire Department when Allibone was removed from service on September 5, 1871. He was promoted to Foreman, a position akin to the modern-day Captain, of Engine Company 1, on June 3, 1873 and served until the spring of 1876. Benjamin Cavanaugh was reappointed in April of 1878 as an extra man with Engine Company 1. He was promoted to stoker of Engine Company 2 on July 2, 1878, replacing William B. Gordon.  Benjamin Cavanaugh's brother Joseph Cavanaugh was appointed to Engine Company 1 as an extra man in September of 1878. The brothers served alongside each other until the spring of 1882, when a change in political power in Camden translated into wholesale personnel changes within the Fire Department. A third brother, John Cavanaugh, served briefly with the Fire Department in the early 1890s.

Benjamin Cavanaugh was born in Canada in March of 1843 to Matthew and Elizabeth Cavanaugh. 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 census shows the family living in Camden's South Ward. Young Benjamin Cavanaugh would start an apprenticeship as a bootmaker during the 1850s

The 1860 Census shows the family still living in Camden's South Ward, Two more children had been born, sons and Matthew Jr. and Joseph Cavanaugh.

When the Civil War came, Benjamin Cavanaugh answered his nation's call. On April 25, 1861 Benjamin Cavanaugh enlisted in the Union Army as a Corporal. He was assigned to Company G, Fourth Infantry Regiment New Jersey on April 27, 1861. 

The Fourth Regiment--Militia, was commanded by Colonel Matthew Miller, Jr., serving under him were Lieutenant Colonel Simpson R. Stroud and Major Robert C. Johnson. This regiment was mustered into the U. S. service at Trenton, April 27, 1861, to serve for three months, and left the state for Washington, D. C., on May 3, with 37 commissioned officers and 743 non-commissioned officers and privates, a total of 777. On the evening of May 5 it reached the capital, and on the 9th it was ordered to go into camp at Meridian hill, where, within a few days the entire brigade was encamped, and where, on the 12th, it was honored by a visit from the president, who warmly complimented the appearance of the troops. On the evening of May 23 it joined the 2nd and 3d regiments and about midnight took up the line of march in silence for the bridge that spanned the Potomac. This bridge was crossed at 2 o'clock on the morning of the 24th, the 2nd was posted at Roach's spring, and the 3d and 4th about half a mile beyond on the Alexandria 
road. On July 16, a guard was detailed from the 4th for a section of the Orange & Alexandria railroad, which it was important to hold; one company from the regiment guarded the Long bridge; still another was on duty at Arlington mills; and the remainder of the regiment, together with the 2nd, was ordered to proceed to Alexandria. On July 24, the term of service having expired, the 4th returned to New Jersey and was mustered out at Trenton, July 31, 1861. The total strength of the regiment was 783, and it lost by discharge 6, by promotion 2, by death 2 and by desertion 7, mustered out, 766.

Benjamin Cavanaugh was among those who mustered out with Company G, Fourth Infantry Regiment New Jersey on July 31, 1861 at Trenton, NJ. 

Several men who served with Company G 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, and William Gleason. Other Fourth Infantry men who served included 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 Fore 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 3, 2011 Benjamin Cavanaugh's 1870 census record has not been located- PMC).

Camden Fire Department records show that from the time he was appointed to the Camden Fire Department in 1871 through at least the spring of 1874, Benjamin Cavanaugh lived at 53 South 4th Street. By May 4, 1875 he had moved to 324 Hamilton Street. Hamilton Street was later renamed Berkley Street. The 1878 City Directory has Benjamin Cavanaugh living at 311 Division Street, and he was still living at 311 Division Street when rejoined the Camden Fire Department in 1879.

In the 1880 Census Benjamin Cavanaugh was counted twice, three days apart, by the same census enumerator, George Bundick. Benjamin Cavanaugh was listed on June 18, 1870 at 311 Division Street, as a member of the fire department, with wife his wife Sarah and sister Fannie. He had been listed on June 15, 1873 as living at 265 Pine Street, the home of his brother-in-law Christopher Mines Jr. Also listed at 265 Pine Street is his brother, Joseph Cavanaugh, then laid up with a broken leg, and their mother. Benjamin Cavanaugh is listed in the 1881-1882 City Directory, compiled after he had left the Fire Department for the last time, as a moulder, living at 311 Division Street.

1882-1883, 1883-1884, and 1885-1888 Directories list Benjamin Cavanaugh at 279 Liberty Street, working as a moulder. In the 1881-1882 edition, he is working at the Camden Iron Works. His employer in the 1885-1888 Directory is Wood & Company. He stayed at 279 Liberty into 1888. The 1890-1891 Directories show the Cavanaugh brothers at 1012 South 2nd Street

The 1891-1892 Directory states that both Benjamin and Joseph Cavanaugh had "removed to Philadelphia". The 1892-1893 Directory, however, gives an address of 815 South 6th Street, Camden. He had gone back to work for the Camden Iron Works. Benjamin Cavanugh is listed in City Directories though the 1894-1895 edition at 815 South 6th Street. The 1895-1896 Directory gives an address of 812 Cammer's Court, which ran south from 512 Pine Street nwxt to Turner's Hall.

The 1897 and 1898 City Directories show Benjamin Cavanaugh at 433 Division Street, and state that he was living with a woman, presumably his wife, named Emma. They were at 405 Division Street in the 1899 City Directory. The 1900 Census has Benjamin Cavanaugh boarding at 230 Division Street, the home of Emma Clare. It is likely that he had been living with Emma for at least 3 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 was still working as a moulder, and single. His brother Joseph Cavanaugh, who was working as a compositor, was also also boarding there.

Neither Benjamin or Joseph Cavanaugh are listed in the 1906 Camden City Directory. Things did not go well for Benjamin Cavanaugh in the 1900s. 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.