"United States Census, 1870," index and images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MC3K-VM6 : accessed 2 June 2015), Martha E Allen in household of William Allen, Georgia, United States; citing p. 61, family 475, NARA microfilm publication M593 (Washington D.C.: National Archives and Records Administration, n.d.); FHL microfilm 545,668.