Tom,

Unless you have the documentation proving otherwise, I highly suspect the Joseph Lightfoot & Emeline Bolden who married 24 December 1868 in Washington County (MS) are the same found in this 1870 household. Ancestry.com provides "Lightford", after comparing the census taker's handwriting, I read this as "Lightfoot".

Name: John Nelson
Birth Year: abt 1837
Age in 1870: 33
Birthplace: Mississippi
Home in 1870: Greenville, Washington, Mississippi
Race: White
Gender: Male
Post Office: Greenville

Household Members:
John Nelson 33 White/Male Retail Merchant
Martha Nelson 30 White/Female Keeping House
Samuel Dun 19 White/Male Clerk In Store
Walter Buttler 18 White/Male Clerk In Store
Joseph Lightford 35 Black/Male Domestic Servant <<<
Emeline Lightford 30 Black/Female Domestic Servant <<<

Hope this helps,
Mitchell Sanders