"United States Census, 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M6VW-FMY : 12 April 2016), Francis Rockwell in household of Thos Rockwell, Dover, Piscataquis, Maine, United States; citing family 15, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).