"United States Census, 1880," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MNQ1-PL9 : accessed 03 Jan 2014), Jonathan Shafer in household of Margarett Grove, Sharpsburg, Washington, Maryland, United States; citing sheet 1B, family 5, NARA microfilm publication T9-0516