Good work!
Take a look at THIS family in Monroe County, MS (1870)¹

Vassas? (indexed Vassar)
Cato? 35 M B Farm laborer AL
Zelphi 30 F B MS
Lou (?) [Laura?] 13 F B MS [indexed as Laura]
Columbus 12 M B "
Elvina? 10 F B [b. ca 1859]
Devida 8 F B [b. ca 1862]
Bowles 4 M B [b. ca 1866]
Doctor 2 M B [b. ca 1868]

There are others with the surname 'Vassas' in 1870 Monroe county.

Some Monroe County Marriages:¹
Elvira Vasser m. Gus Love 23 Oct 1877 Monroe
Laura Vasser m. Tom Beeks 2 Aug 1876 Monroe

¹ Ancestry.com. 1870 United States Federal Census [database on-line]. Provo, UT, USA: MyFamily.com, Inc., 2003. Original data: United States. Ninth Census of the United States, 1870. Washington, D.C. National Archives and Records Administration. M593, RG29

² Hunting For Bears, comp.. Mississippi Marriages, 1776-1935 [database on-line]. Provo, UT, USA: MyFamily.com, Inc., 2004. Original data: Mississippi marriage information taken from county courthouse records. Many of these records were extracted from copies of the original records in microfilm, microfiche, or book format, located at the Family History Library.