SC 39 Edgefield to Moneta 1922 Auto Trails

SC 39 extended to Perry 1923 Auto Trails

In 1924, SC 39 was extended south replacing part of SC 1 to end at SC 4 Springfield.
In 1925 or 1926, SC 39 was extended as new primary routing from Edgefield west to end at SC 20 (now US 221/SC 28) Modoc and southwest from Springfield replacing part of SC 4 to end at SC 27 (now US 78) Williston.

SC 39 extended to Sprinfield 1924 Blue Book

SC 39 extended both directions 1926 Official

In 1935, SC 39 was rerouted at Ridge Spring to instead replace SC 392 northwest through Saluda to Cold Point. The route west to Modoc became part of SC 23.

SC 392 Ridge Spring to Cold Point 1926 Official

SC 392 reduced to current routing 1935 Official

In July 1936 (SCDOT), SC 39 was extended west as new primary routing from Cold Point through Ware Shoals to end at US 178 Shoals Jct. Some of this was a mileage swap with SC 10 by Act of SC Legislature.
Also in July 1936 (SCDOT), SC 39 was extended southwest from Williston as new primary routing to end at SC 64 (now SRS B) Dunbarton.
SC 39 was removed from Soule Chapel Church Rd/Poplar Springs Rd loop south of Cross Hill by 1940.
In 1940, SC 39 was extended south as new primary routing to end at SC 28-282 (now SC 125) near Millet.
In 1941, SC 39 was extended south over SC 282 to end at SC 282 in Millett.
In 1947, SC 39 south was truncated to SC 64 Dunbarton, leaving behind S-6-15 (now SRS 8), S-3-24, and S-3-17.
Also in 1947, SC 39 north was truncated to Cold Point, leaving behind S-30-6 and US 25. A discontinuous piece of SC 39 remained from Shoals Jct to Ware Shoals.
In 1950, the SC 39 piece between Shoals Jct and Ware Shoals was renumbered as SC 420.

SC 39 extended west to US 178 1937 Official

SC 39 discontinuous piece 1949 Official

SC 420 replaces SC 39 1951 Official

In late 1952, SC 39 south was truncated to SC 28 (now US 278) at the Savannah River Site boundary. The old route south to Dunbarton is now SRS routing, except a couple pieces near Dunbarton are underneath Par Pond.

SC 39 extended south to Dunbarton 1937 Official

SC 39 extended south to SC 28-282 1940 Official

SC 39 extended south to Millett 1941 Official

SC 39 truncated to Dunbarton 1948 Official

SC 39 truncated to SRS boundary 1953 Official

Improvements: Around 1929, SC 39 was paved from Johnston to US 1.
SC 39 was paved from Edgefield to Johnston in 1934.
In 1935, SC 39 was paved from Wagener to Perry.
In 1936, SC 39 was paved from Saluda to Chappells and from Cross Hill to Cold Point.
In 1937, SC 39 was paved from Williston to Springfield; also from Ridge Spring to Saluda; also Chappells to Cross Hill except from SC 56 to the Laurens County Line; also Shoals Jct to Ware Shoals.
In 1939, SC 39 was paved from Springfield to Perry, also the gap at SC 56 was paved.
In 1940, SC 39 was paved from Dunbarton to Williston.
In 1941, SC 39 was paved from Wagener to SC 391.
The last piece of SC 39 to be paved was SC 391 to US 1, between 1943-46.
There are no multilane segments on SC 39.
Comment: SC 39 is one of the longer state routes that I have driven very little. As designated, it does not constitute a through route to much of anywhere.