Alexander Curtis was born in 1850 in Pennsylvania. His parents had been born in Pennsylvania as well. In 1875 he married Frances, who was born in Germany in 1855. They had two daughters, Jennie and Daisy. The family lived in Missouri for at least four years before moving to Chicago in 1880. In the 1880 U.S. census for Chicago Ward 9 under "Occupation," Alexander Curtis is listed as "Pedaler" and his wife as "Keeping house."