"United States Census, 1850," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MCDT-91G : accessed 25 Aug 2014), Mary Mason in household of Sam Mason, Monroe county, Monroe, Tennessee, United States; citing family 675, NARA microfilm publication M432.
"United States Census, 1860," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MXHR-1HN : accessed 25 Aug 2014), James Mason, Brooklyn Township, Schuyler, Illinois, United States; citing "1860 U.S. Federal Census - Population," Fold3.com; p. 236, household ID 1558, NARA microfilm publication M653; FHL microfilm 803228.
It may be possible to confirm family relationships with Mary by comparing test results with other carriers of her mitochondrial DNA.
However, there are no known mtDNA test-takers in her direct maternal line.
It is likely that these autosomal DNA test-takers will share DNA with Mary: