SC 6 Charleston to Orangeburg via Walterboro 1922 Auto Trails

SC 6 extended northwest to Chapin 1926 Official

By 1926, SC 6 was removed from S-15-67/S-15-24 between Ruffin and Smoak and placed on modern US 21; also SC 6 was removed from Kristin Ave/S-15-371/S-15-41
In 1927 (bridge date), SC 6 was removed from Old Jacksonboro Rd between S-10-40 Parkers Ferry west to the Edisto River.
In 1928, SC 6 south was truncated to Orangeburg. Orangeburg to south of Ruffin became US 21; east to Walterboro became SC 64; Walterboro to Charleston became US 17. Today this is 21 Business; US 21 to Rowesville; S-38-117 to Branchville (it is unclear if SC 6 was moved to modern US 21 before 1928 or not); US 21 south to SC 64; SC 64 east to Jacksonboro except: S-15-208 Dorsey Rd northwest of Walterboro, SC 64 Business through Walterboro; US 17 to Parkers Ferry; S-10-40; SC 174; SC 162; US 17 to Charleston; S-10-3 to King St. As best I can tell, SC 6 never used the lengthy Old Jacksonboro Rd from Osborn east past today's SC 165.

SC 6 truncated to Orangeburg
1928 Standard Draft

Between 1927-29, SC 6 was removed from Peachtree Rock Rd south out of Edmund.
In 1929, SC 6 was rerouted at Lexington to instead meet US 76/SC 2 at Ballentine via newly constructed routing over the Lake Murray Dam. The old route was secondary on both sides of Lake Murray (S-32-83 Old Lexington Hwy and S-32-52 Old Chapin Rd today) although the southern segment was part of SC 552 in the 1940s.
Also in 1929, SC 6 south was rerouted at North to replace SC 24 south through Norway and Denmark to end at SC 64 Olar. The old route from North to Orangeburg became part of SC 24 (now US 178 and US 178 Business).

SC 6 rerouted to Ballentine north of Lexington 1930 Official

SC 6 rerouted south to Olar 1930 Official

In 1936 or 1937, SC 6 was shown as a projected road from SC 64 Olar south to SC 33 (now US 301) near Ulmers.
In 1939, SC 6 was rerouted at Swansea to replace SC 45 east through St Matthews to Eutawville, then replaced SC 46 east to Moncks Corner.

SC 45 Swansea to Eutawville 1930 Official

SC 6 replaces SC 45 to Eutawville 1940 Official

The route from Swansea south to Olar was renumbered as SC 5 (now US 321).

SC 6 projected to head south of Olar 1937 Official

SC 5 replaces SC 6 south to Olar 1939 Official

In 1942, SC 6 was rerouted around the newly built Pinopolis Reservoir (Lake Moultrie) replacing parts of SC 260 and SC 311 plus new construction. The road between Pinopolis and Moncks Corner became SC 668 (now S-8-5).

SC 46 out of Moncks Corner 1923 Auto Trails

SC 6 replaces SC 46 1939 Official

SC 6 rebuilt around Lake Moultrie 1942 Official

About 2018, SC 6 was placed on one-way splits in Lexington. WB used the original route of Lake Dr. EB now uses Church St and Maiden Ln. This change also eliminated a posted SC 6 West Truck for US 1 SB traffic that followed US 1 south to US 378 back to SC 6.
Improvements: SC 6 was paved from Charleston over to around Ravenel by 1923.
In 1927, SC 6 was paved from Rowesville to Orangeburg.
In 1928, the remaining SC 6 was all unpaved.
In 1929, SC 6 was paved from Swansea to North.
In 1931, SC 6 was paved from Lexington to Ballentine.
In 1932, SC 6 was paved from North to Denmark.
In 1934, SC 6 was paved from Lexington to Edmund and also from Denmark to Olar.
In 1937 SC 6 became fully paved from Olar to Ballentine.
In 1939 after the major SC 6 rerouting, SC 6 was paved from Ballentine to Swansea; US 21 (current US 176) to Santee; Pinopolis to Moncks Corner.
In 1942, SC 6 was paved from Santee to Eutawville.
Between 1943-46 SC 6 was paved from Swansea to St. Matthews and also from SC 311 to Moncks Corner.
In 1949 SC 6 was paved from Eutawville to the Berkeley County Line.
The remaining piece of SC 6 from the Orangeburg-Berkeley Line to SC 311 was paved in 1950.
SC 6 was 4-laned on its US 378 duplex in 1978.
In 2009, SC 6 was multilaned from US 378 to SC 60.
In 2012, SC 6 was multilaned from SC 602 to a little north of I-20
Comment: SC 6 bears no resemblance to its original routing anymore.
There is a posted SC 6 TRUCK in Moncks Corner that uses US 17 ALT and US 52.
SC 6 bears the distinction of being underneath parts of 2 lakes; it crosses the Lake Murray Dam directly and is often very close to the Lake Moultrie southern berm.
Thanks to Dave Darby for historical input on SC 6.