Robert was born between 1675 & 1680 in Virginia. He was the son of Francis Slaughter and Margaret Hudson. Robert married Frances Ann Jones, daughter of Lt. Col. Caldwalder Jones, about January 1700 in St. Mark's Parish, Spotsylvania County, Virginia. The Parish was established by Act of Assembly in 1730 and antedates Culpeper County by eighteen years, Culpepper County being laid off from Spotsylvania in 1748. St. Mark's Parish Register is the oldest manuscript in Culpeper Co. Robert had three sons. He owned extensive amounts of land in Spottsylvania County, Virginia, part of which was transferred to his sons during his lifetime, and the rest was bequeathed to them by his will. Robert made his will on February 5, 1725 and it was probated on August 16, 1726. Frances was alive at the time the will was written.