I found an 1866 marriage record in Massachusetts for Walter Flint who lists his parents as Samuel Flint and Mary Morris: "Massachusetts, Town Clerk, Vital and Town Records, 1626-2001," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:FHW2-Y7X : accessed 11 March 2016), Samuel Flint in entry for Walter M. Flint and Francena Parker, 09 Jan 1866; citing Marriage, , Worcester County, Massachusetts, United States, , town clerk offices, Massachusetts; FHL microfilm 2,209,400.
If this record isn't for your Samuel and Mary, could you provide any dates (even approximate dates) for either of them? That might help someone to locate better information.