2, 1864 Benjamin Kellum enlisted as a Private with Company D, 2nd New Jersey Cavalry Regiment, a unit which was also referred to as the the 32nd New Jersey Volunteers. The United States went to war with itself in 1861. Not long after his sixteenth birthday, on September 2, 1864 Benjamin Kellum enlisted as a Private with Company D, 2nd New Jersey Cavalry Regiment, a unit which was also referred to as the the 32nd New Jersey Volunteers. When Private Kellum enlisted the regiment was quartered in Memphis, Tennessee. Being ordered into Arkansas and disembarking at Osceola, the command crossed a swamp some 18 miles in length, the mud and water reaching to the saddle-girths of the horses, to Big lake, where after some brisk firing a Confederate train consisting of some 18 wagons, loaded with over 900 stand of arms of approved pattern, together with 
11 prisoners and 2 commissioned officers, was captured. Reaching Verona, Miss., on Dec. 25, the command at once charged gallantly on the enemy, who was completely surprised and offered but a feeble resistance, most of them escaping into the timber under cover of the darkness leaving as spoils, eight buildings filled with fixed ammunition, estimated at 30 tons, 5,000 stands of new carbines, 8,000 sacks of shelled corn, a large quantity of wheat, an immense amount of quartermaster stores, clothing camp and garrison equipage, a train of cars and a large number of army weapons which had been captured by 
Confederate General Nathan Bedford Forrest from General Sturgis during the latter's disastrous expedition in June. 

The regiment also participated in the fight at Egypt Station, on December 28, 1864 in which 74 men and over 80 horses of the 2nd N. J. were killed or wounded. As part of as expedition sent out from Memphis to destroy the Mobile & Ohio railroad, 2nd New Jersey along with the 7th Indiana, 4th and 11th Illinois, 4th and 10th Missouri, 2nd Wisconsin, 1st Mississippi, and 3rd U.S. Colored Cavalry attacked the enemy at Egypt Station, Mississippi. The Confederate force was about 1,200 strong and consisted of infantry, cavalry and 4 guns mounted on platform cars. Two trains of Confederate troops under Major General Gardner were in sight when the attack was made, but a Federal force being thrown between them and the stockade, which was taken by assault in 2 hours, they were unable to do anything. The entire garrison, numbering 500, were made prisoners. The casualties are not given, but it is noted that Confederate Brigadier General Gholson was killed. The Union force also captured or destroyed 300 army wagons, 4,000 new carbines, an immense amount of ammunition, two trains of cars and a large amount of commissary and quartermaster's stores.

The regiment returned by steamer to Memphis, having lost during the entire expedition 19 men killed, 69 wounded and 2 missing, and 155 horses and mules killed or disabled. The regiment campaigned in Mississippi and Alabama in March and April of 1865. Its last action occurred on April 28, 1865 at Clayton, Alabama.

Private Benjamin L. Kellum mustered out of Company D, 2nd Cavalry Regiment New Jersey on June 29, 1865 at Vicksburg, Mississippi. He subsequently returned to his home and family in Camden. He reenlisted in 1866 and served another three years with the Sixth Cavalry Regiment before returning home for good upon discharge in April of 1869.

The 1870 Census shows Benjamin Kellum living with his mother, step-father, and siblings in Camden's Middle Ward. His stepfather was working in a store, while Benjamin and younger brother Jacob Kellum worked as laborers. 

Benjamin Kellum was appointed to the Camden Fire Department in the on May 7, 1874 as an extra man with the Hook & Ladder Company, joining his brother Jacob. The brothers served together with the Camden Fire Department for most of the rest of their working days. 

Benjamin Kellum was promoted to Driver of the Hook & Ladder Company on November 12, 1874 to take the place of William Alcott, who had passed away on November 4. He was then living at 450 Henry Street and had been working as a laborer. Benjamin Kellum remained in the post of Driver until April 8, 1876 when he and many other Camden fire fighters were replaced for political considerations. Still living at 450 Henry Street, Benjamin Kellum was reappointed on April 8, 1877. He served for five years before again being dismissed from the department for political reasons. He returned in 1885, and remained a Camden Fire Department member until retiring in 1903.

The 1878 City Directory gives Benjamin Kellum's address as 451 Henry Street. The 1880 Census shows Benjamin Kellum and his wife Annie living at 411 Bridge Avenue. The 1882-1883 Directory shows him back at 451 Henry Street. 1884 has an address of 422 Berkley Street, 1885 has him living at 424 Berkley Street. 1887 Shows him living at 528 Lawrence Street. The next Directory, 1888-1889 gives an address of 534 Washington Street. The 1890-1891 and 1891-1892 editions have Benjamin Kellum at 524 Washington Street. The 1892-1893 Directory indicates a move to 516 Clinton Street. Benjamin Kellum remained at 516 Clinton Street into 1899, then moved to East Camden, taking up residence as well as responsibilities with the Fire Department in the wake of that year's merger of the City of Camden and the Town of Stockton, which brought East Camden and Cramer Hill into the city.

Benjamin Kellum remarried around 1884. He and his wife Margaret "Maggie" Kellum were not, however, blessed with children. They did raise a nephew, Harry Suters, who live with them in the 1890s and 1900s, and stayed with Mrs. Kellum after her husband's death.

Benjamin Kellum was an active member of the Thomas M.K. Lee Post No. 5, G.A.R.. The post's membership included many other prominent Camden citizens, and Camden Fire Department members Theodore Verlander, J. Kelly Brown, Jesse Chew, William Gleason, Thomas R. Grapevine, Frank S. Jones, William H. Shearman, William T.G. Young, and Charles G. Zimmerman.

By 1894 Benjamin Kellum had been promoted to foreman of what is now Ladder Company 1, a position equivalent to today's Captain. In November of 1899 he was promoted to Assistant Chief, the equivalent of today's Deputy Chief.

The 1900 Census lists Benjamin and Margaret Kellum, and their 15 year-old nephew Harry Suters, at 15 South 35th Street in East Camden. When grown to adulthood, Harry Suters would serve with the Fire Department for a few years. A young boy  who lived next door, David W. Humphries, joined the Camden Fire Department in the 1920s; his brother Elwood Humphries became a Camden police officer.

Benjamin Kellum and family had moved to 13 South 34th Street by 1906. 

Benjamin Kellum contracted tuberculosis in the early 1900s, and retired on half-pay from the Camden Fire Department effective August 1, 1903. He died on March 31, 1909, survived by his wife, nephew, and siblings. His younger brother, Jacob Kellum, continued to serve as a member of the Camden Fire Department. He was still on active duty in January of 1920.

Benjamin Kellum's cousins, Robert Todd and Charles A. Todd, both served with the Camden Fire Department.