SC 28 ALT #1: Appeared in 1936 or 1937 as new primary routing running as a stub from SC 28 (now SC 125) to Ellenton.
In 1942, SC 28 ALT was renumbered as SC 649. Today it is part of SRS route 3.

SC 28 ALT to Ellenton 1940 Aiken County

SC 649 appears at Ellenton 1942 Official

SC 28 ALT #2: Appeared in 1938 as a renumbering of SC 20 ALT from SC 28 McCormick south back to SC 28.
In 1947, SC 28 ALT was downgraded to S-33-11

SC 20 ALT southeast of McCormick 1937 Official

SC 28 ALT southeast of McCormick 1938 Official

SC 28 ALT #3: Appeared in 1938 as a renumbering of SC 18 ALT as a cutoff between SC 184 and SC 28-284 north of Antreville.
In 1947, SC 28 ALT was downgraded to S-1-12 (now S-1-270).

SC 28 ALT #4: Appeared in Oct 1938 (SCDOT) as new BELT primary routing on Magnolia St and Lee Ave in Hampton.
In 1947, SC 28 ALT was downgraded to S-27-11 (Magnolia St is now S-27-83).

SC 28 ALT #3 north of Antreville 1940 Abbeville County

SC 28 ALT #4 in Hampton 1940 Hampton County