SC 33 original routing (avoidance of Bamberg is a map error) 1922 Auto Trails

SC 33 extended to Hardeeville 1926 Official

About 1928, SC 33 was extended east from Hardeeville as new primary routing to end at Bluffton.
In July 1936 (SCDOT), SC 33 was extended through Bluffton to end at Brighton Beach. The original SC 33 ending at the May River waterfront became SC 33 ALT (now S-7-66 and S-7-31).
In 1939, SC 33 south was truncated to SC 5 (now US 321) north of Ulmers leaving behind SC 5 to Hardeeville, SC 5 ALT in Hardeeville and SC 46 to Brighton Beach. Today this is US 321, SC 46, S-7-66 and S-7-13. SC 33 almost certainly used S-27-176 loops east of Hardeeville.

SC 33 extended to Bluffton (mislocated on the map!) 1930 Official

SC 33 extended past Bluffton 1938 Official

SC 33 removed from the area 1939 Official

Also in 1939, SC 33 was extended with SC 4 into Orangeburg, then replaced SC 69 to end at SC 6 Creston. Some of this was newly constructed alignment.
In 1940, SC 33 was extended northeast as new primary routing to end at SC 47 (now SC 267) Lone Star.
In 1947, SC 33 south was truncated to US 301 (now S-38-1) in eastern Orangeburg. The route to Ulmers became part of US 301.

SC 69 Orangeburg to Cameron 1937 Official

SC 33 replaces SC 69 1939 Official

SC 33 extended to Lone Star 1940 Official

SC 33 truncated to Orangeburg 1948 Official

In 1954, SC 33 was re-extended through Orangeburg to its current endpoint, replacing US 301.

SC 33 ending at US 301 Dorchester Rd 1951 Official

SC 33 ending at US 301-601 southwest of downtown 1955 Official

Improvements: The first piece of SC 33 to be paved was between Hardeeville and Bluffton, in 1931.
SC 33 was paved between Garnett and Fairfax in 1933.
In 1934, SC 33 was paved between Hardeeville and Garnett and from Bamberg to Orangeburg.
In 1935, SC 33 was paved from Fairfax to Sycamore.
In 1937, SC 33 was paved from Sycamore to the Allendale-Bamberg Line.
The remainder of SC 33 from there to Bamberg was paved in 1939.
SC 33 was paved from Orangeburg to Cameron when designated in 1940.
The remainder of SC 33 was paved by 1948.
SC 33 was multilaned from Orangeburg out to I-26 in 1979.
Comment: SC 33 serves the lovely Edisto River Gardens, as well as downtown Orangeburg.