The Murdaugh family was prominent in a sub-region of South Carolina known as The Low-Country, which is basically the combined coastal areas surrounding Charleston and Hilton Head Island, SC, and Savannah, GA. The name refers to the region's terrain, which is entirely flat and at/near sea-level. While the preponderance of events depicted in the series occurred in The Low-Country, most of the show was actually filmed in the areas surrounding Atlanta, GA (approx. 300 miles west of where the events actually took place).
"Murdaugh: Death in the Family" is set in South Carolina.