His father was James Edgar Steuart. He lived I Baltimore, MD all his life and died in 1870.

His mother was Sarah Mateer of Baltimore.

His wife was Emily J Nourse, and she was born July of 1841 in MD, and after the death of her husband, she moved to Washington, D.C. with family.

They were married on September 4th, 1860 in Texas.

They had 3 kids. William (Director of the US Census- 1921 to 1933), Alice, and Alexander Jr.