This Benjamin did not marry Mary Sears. Her name may have been Nancy Thompson. See recent resarch and theories in Ancestry.
or contact Tom Grissom at tgrissom@crosstel.net for sources and how he figured out the names of wives. It was Benjamin Jr who died in 1808 that married Mary Sears https://www.ancestry.com/family-tree/person/tree/6989691/person/150...
There were two Benjamin Grissoms in NC at the same time and separating the father from the son was difficult.
Thanks,
Mary