Like many of those who immigrated to South Carolina from Ireland, the Petigrus (or Pettigrews, as they were styled in several generations) had a past tainted by association with tyranny – in this case, with Oliver Cromwell's Irish campaign in which the original James Louis Petigru was involved in the mid seventeenth century.

 

The family had come from France to Scotland several generations before, and, some few generations after the Cromwellian invasion, produced a William Pettigrew, who was an officer in the Williamite army that defeated the Catholic forces led by King James at the Battle of the Boyne in 1690. According to most accounts, the family had already acquired an estate of some three hundred acres near Aughnacloy, Co. Tyrone, and built a house there about 1682 (though some sources suggest that this was acquired later as a reward for William's valor at the Boyne).