He was present at Yorktown when Cornwallis surrendered, later receiving the rank of Brigadier General. He returned to Frederick, Maryland after the war, where he resided until his death on June 7, 1815.

In 1835, Emily Nelson, daughter of General Nelson and Betty Harrison Nelson, married William Pickney Maulsby, who became Chief Judge of the 6th Judicial Circuit of Maryland. Of this union, eight children were born, five of whom died in childhood. Their son, William Pickney Maulsby, Jr., married Henrietta Pigman. The second child, Emily Nelson Maulsby, married Henry Kimball of Kanosha, Wisconsin.

The third child, Betty Harrison Maulsby, married Judge John Ritchie. Mrs. Ritchie became a member of NSDAR, May 25, 1892. She served as Regent of the Frederick, Maryland, Chapter, State Regent of Maryland, and as Vice President General, NSDAR. Her mother, Mrs. William P. Maulsby, died in 1867, a member of the Episcopal Church, and is buried in Mount Olivet Cemetery near Frederick, Maryland.

The eldest daughter of Judge Ritchie and Betty Harrison Maulsby, Emily Nelson Ritchie, married Donald McLean of New York. She was a charter member of NSDAR and a charter member of the New York City Chapter, serving as its Regent from 1895 to 1905. In 1905, she was elected President General, NSDAR, serving two terms 1905-1907 and 1907-1909. The new Chapter formed on January 11, 1907, was named Emily Nelson in her honor, and in honor of her grandmother.