| mid-1920s – present|
US 76 in Florence
NC 51 in Pineville, NC
| US 701 near Georgetown|
US 21 near Ft. Mill
| US 378 / SC 41 near Johnsonville
US 301 in Florence
US 52 in Florence|
Georgetown County, South Carolina
South Carolina Highway 51 (SC 51) is a primary state highway in the U.S. state of South Carolina. It is unique for being signed in two different locations in the state; the first section from Georgetown to Florence, the second section in Fort Mill.
South Carolina Highway 51 Wikipedia
The first SC 51 begins at US 701 near Georgetown, goes northwest and ends at US 76 in Florence and concurrency with SC 41. Majority of the route is a two-lane rural road, except through Hemingway, Johnsonville, and Florence, where it has four lanes.
The second SC 51 is a short 1-mile-long (1.6 km) road that starts at US 21 and ends at the North Carolina state line, continuing on as NC 51 through Pineville. The route is only 2-lane, expanding to 4-lane at the state line.
Established as a new routing in either 1925 or 1926; the original route ran from SC 40 (today as US 701) along Choppee Road to Hemmingway then onto Florence, ending at SC 41 (current US 52-301). The route was fully paved by 1939. In the early 1960s, the SC 51 was rerouted as a concurrency with SC 41 from Hemmingway to Rhems, then to US 701 near Georgetown. In 1978, SC 51 was extended in Florence to US 76.
The second SC 51 was established in 1969, when US 21 was rerouted to its current alignment to I-77. The number was a result of an extension of NC 51 that replaced the old US 21 route through Pineville. SC 51 is a result of keeping the route consistent across the border.