Lieutenant Inslee Anderson was born in Pennsylvania, the younger brother of Captain Enoch Anderson, an officer of the Delaware Regiments who served throughout the Revolutionary War. Inslee followed his brother into military service, serving as a Cadet in Colonel Thomas Proctor's Regiment of Artillery- the same regiment that produced Major William Ferguson, also buried at Fort Recovery. He fought at the Battles of Brandywine and Germantown before leaving the Continental Army. It was his brother Enoch who subsequently secured him a new commission, writing later in his published memoirs that "I got him a commission of adjutant in Colonel Gibson's Regiment." The name "Inslee" itself was a family surname carried forward as a given name, a common practice in 18th-century American families, reflecting the tight-knit family networks that characterized both civilian and military life in the early republic.

On June 21, 1791, Anderson was appointed a Lieutenant of Captain Slough's company in the East Pennsylvania Battalion of the Second Regiment of Levies. Upon his arrival at Fort Pitt in June, he was appointed Regimental Adjutant to Major Thomas Butler's East Pennsylvania Battalion. He participated in the full Northwest Territory military campaign of 1791 under General Arthur St. Clair, serving in an administrative and organizational role that was critical to the functioning of the regiment. His death on November 4, 1791 was documented in General St. Clair's official letter to Secretary of War Henry Knox, dated Fort Washington, November 9, 1791, a letter transmitted by President Washington to Congress on December 12, 1791, and reported in the Delaware Gazette on December 17, 1791. Notably, he was listed alongside Captain Robert Kirkwood - another man honored on this memorial - in that official report.

Lieutenant Inslee Anderson was killed in action during the battle on the upper Wabash River on November 4, 1791. His brother Enoch, writing decades later in his memoirs, recorded his death with quiet grief alongside his own recollections of thirteen battles "great and small." His remains are buried in one of the mass graves beneath the monument at the center of Fort Recovery, Ohio, not far, in a sense, from the regiment of Captain Robert Kirkwood with whom his name was forever linked in St. Clair's final report to the President of the United States.