SC 26 from Sumter through Lancaster to North Carolina 1922 Auto Trails

SC 26 from Sumter to Georgetown 1922 Auto Trails

In 1925 or 1926, SC 26 south was truncated to SC 41 (now S-45-8) Kingstree. The route to Georgetown became secondary except for the first few miles out of Georgetown which remained SC 40 (now US 701). Today the route via Rhems appears to have been SC 51, unpaved Rhems Rd, S-45-42, S-45-383, SC 527, SC 377-527 CONN, SC 377, and SC 261.
In 1928, SC 26 was re-extended replacing SC 412 and SC 44 through Andrews to again end in Georgetown.

SC 26 truncated to Kingstree 1926 Official

SC 26 replaces SC 44 back to Georgetown 1930 Official

About 1929, SC 26 was removed from today's S-29-378 and abandoned routing north to where US 521 and S-29-125 meet today - this means SC 26 went briefly into North Carolina and actually intersected with NC 25, which moved to today's NC 75 location when SC 26 was shifted west.
Also, if SC 26 ever used S-29-284 between Heath Springs and Elgin it stopped doing so by 1929 or thereabouts.
In 1933, SC 26 was renumbered in its entirety as US 521. It is still US 521 except: US 521 Business through Andrews; SC 377 into Kingstree; abandoned causeway across the Black River; SC 261 to Manning; US 301 CONN through Alcolu; S-14-401 north of Alcolu; S-43-1496 and S-43-152 into Sumter; SC 763 and US 76 Business out of Sumter; S-43-1342 through Dalzell; S-43-2/S-28-2/SC 261 in the Boykin area; US 521 Bus and S-29-2 through Lancaster.

US 521 replaces SC 26 north of Sumter 1933 Official

US 521 replaces SC 26 south of Sumter, too. 1933 Official

SC 26 #2: Appeared in 1935 as a renumbering of SC 52, running from US 21 (now US 21-176 jct) St. Matthews north through Eastover to end at US 76 near the Wateree River.
In July 1936 (SCDOT), SC 26 was extended north to the Kershaw County line.
In May 1937 (SCDOT), SC 26 was extended north to US 1 Lugoff.
In Nov 1937 (SCDOT), SC 26 was placed on new routing to bypass Eastover, then take a more direct route to US 76, then continued as more new primary routing to end at US 1 Lugoff. The old loop through Eastover became SC 26 ALT. Today it is SC 764 and SC 263 through Eastover.
In 1940, SC 26 was sraightened out in its southern approach to Richland County leaving behind what is now part of S-27-47

SC 26 indirect routing into Richland Co 1938 Kershaw County

SC 26 straightened routing into Richland Co 1942 Kershaw County

About 1948, SC 26 was given a new crossing of the Congaree River including a substantial new approaches on both sides. The approaches were shown as unnumbered primary routes as early as 1942. The old approaches to the river became what is now S-9-151; unnumbered dirt road to the former Congaree River Bridge location; abandoned causeway south of Little Creek north of the Congaree;

SC 26 original Congaree River crossing 1943 Calhoun County

SC 26 modern Congaree River crossing 1950 Calhoun County

In 1950, SC 26 was extended south replacing US 21 to end at US 301 (now SC 33) Orangeburg.
In 1951, SC 26 was renumbered as part of US 601.

SC 52 from US 21 to US 76 1930 Official

SC 52 replaced by SC 26 1935 Official

SC 26 extended north to US 1 1938 Official

SC 26 replaces US 21 to Orangeburg 1950 Official

SC 26 replaced by US 601 1951 Official