[20]
Arthur had seven siblings who lived to adulthood:[21]

Regina (1822–1910), the wife of William G. Caw, a grocer, banker, and community leader of Cohoes, New York who served as town supervisor and village trustee[22]
Jane (1824–1842)[23]
Almeda (1825–1899), the wife of James H. Masten who served as postmaster of Cohoes and publisher of the Cohoes Cataract newspaper[24]
Ann (1828–1915), a career educator who taught school in New York and worked in South Carolina in the years immediately before and after the Civil War.[25]
Malvina (1832–1920), the wife of Henry J. Haynesworth who was an official of the Confederate government and a merchant in Albany, New York before being appointed as a captain and assistant quartermaster in the U.S. Army during Arthur's presidency[26]
William (1834–1915), a medical school graduate who became a career Army officer and paymaster, he was wounded during his Civil War service.  William Arthur retired in 1898 with the brevet rank of lieutenant colonel, and permanent rank of major.