He was the eldest son of William Nelson and Ann Leap Mills, named after his maternal grandfather, Jacob Leap, Sr. We knew of his existence but not his name from the US Census records of 1810, the Alexandria City tax list of 1812. He appeared as a “male child under age 5 years” on the census. These records listed only the name of the head of household (William Nelson Mills); other persons in the household were counted by age group and gender, but not by name. A power of attorney document dated October 22, 1852 was the key to discovering his given name, Jacob Mills. The POA was included in the deed of sale of property originally owned by Jacob Leap, Sr. This property was willed to his grandchildren who were still alive at the time of his death on December 15, 1820, and they were listed by name in the document: Jacob Mills, deceased, William Robert Mills, Thomas M. Mills, Albert N. Mills, and John R. Mills.
It was only by chance we discovered the name of Jacob Mills in the power of attorney document, and that was the only reference we found of him in Alexandria records. Consequently, we do not know the conditions surrounding his death or when he died. We feel certain Jacob Mills is buried in First Presbyterian Cemetery in Alexandria alongside his sister, Adeline Margaret Mills, his parents and grandparents. Our visit to the cemetery revealed there were at least three graves for which tombstones are missing: Ann Leap, wife of Jacob Leap, Sr.; Jacob Leap, Jr., their son; and Jacob Mills, son of William Nelson and Ann Leap Mills. Apparently, the stones were removed, destroyed, or lost over the past two hundred years.