SC 90 Conway to Wampee 1930 Official

SC 90 extended to US 17 1935 Official

In 1937, SC 90 was extended west as new construction to the rerouted US 501 (now US 501 Bus). This left behind the original west ending of SC 90 along today's S-26-345 Dobros Rd. SC 90 was then extended with US 501 into Conway, then west as new primary routing by Act of SC Legislature to end at SC 175 (now S-34-9) near Gresham.
In 1938, SC 90 was rerouted in southern Marion County to instead head north to SC 175 (now SC 41) near Brittons Neck.
In 1939, SC 90 was rerouted in Marion County again to head to Gresham. The route north to Brittons Neck became SC 908.

SC 90 extended west to SC 175 1937 Official

SC 90 changed to run north 1938 Official

SC 908 replaces part of SC 90 1939 Official

By 1940, SC 90 was removed from Steritt Swamp Rd; Isaac Rd and a lengthy Old State Hwy 90 at Nixonton;
The 1941 Official shows SC 90 west of SC 908 as a projected road (1937, 1939, and 1940 Officials all show an actual road, while the 1940 Marion County map shows a gap in SC 90 with the western part using today's S-34-206 from Gresham to S-34-206 and the eastern part ending at the SC 90-908 jct with no road at all between the two parts. The 1943 Marion County map removes SC 90 from the western part and instead shows a projected SC 90 road from SC 908 to SC 175 near the Pee Dee River Bridge.

SC 90 split routing near Gresham 1940 Marion County

SC 90 projected routing near Gresham 1943 Marion County

In 1952, SC 90 west was truncated to its current Conway endpoint leaving behind US 501 into Conway, and US 378 west to today's SC 41. Official maps up through 1951 continued to show west of SC 908 as projected roadway.

SC 90 changed to run north 1941 Official

SC 90 becomes US 378 west of Conway 1952 Official

In 1970, SC 90 was extended east over US 17 to the current SC 90 endpoint.

SC 90 ends at Nixon Crossroads 1968 Horry County

SC 90 extends north to new US 17 alignment 1974 Horry County

About 2009, SC 90 was rerouted slightly to accommodate the construction of the Robert Edge Parkway, leaving behind abandoned routing. This provides SC 90 with nearly direct access to the SC 31 freeway which up to this point there had been no access of any kind.
Improvements: The first few miles east of Red Hill were paved in 1938
All of SC 90 east of Red Hill was paved in 1939
In 1940, SC 90 was paved 5 miles westward from Conway.
In 1941 or 1942, SC 90 was paved west to the Little Pee Dee River.
By 1948, SC 90 was paved west to SC 908.
SC 90 is multilane only in the immediate vicinity of Robert Edge Pkwy.
Comment: SC 90 serves eastern Horry County.
SC 90 along with S-26-57 and US 701 make a decent Grand Strand Bypass.