SC 1: transferred to US 17 from Georgia to Yemassee, renumbered SC 28 from Yemassee to Allendale, and renumbered SC 3 from Allendale to Dixiana.
SC 2: overlapped US 76 from Greenville to Columbia, US 21 from Columbia to Orangeburg, and US 78 from Dorchester to Charleston; route remained due to the historical significance of the highway
SC 3: transferred to US 76 from Columbia to Florence and US 17 from Florence to North Carolina; reassigned as a renumbering of the last portion of SC 1 from Allendale to Dixiana
SC 6: truncated; transferred to US 21 from Orangeburg to Ruffin, SC 64 from Ruffin to Walterboro, and US 17 from Walterboro to Charleston
SC 7: truncated; transferred to US 21 from Chester to North Carolina
SC 8: transferred to US 29; reused as a renumbering of SC 13
SC 12: transferred to US 1 from West Columbia to Georgia; reused on a route from SC 26 (now US 521) to nearby NC 25 (now NC 75)
SC 13: renumbered SC 8; reused as a renumbering of SC 17 to match Georgia
SC 16: truncated; transferred to US 21 from Columbia to Chester
SC 17: renumbered SC 13
SC 19: truncated and extended; transferred to US 176 from Newberry to North Carolina; extended over SC 27 from Trenton to Aiken
SC 21: transferred to US 25
SC 23: transferred to US 217 from North Carolina to Pee Dee; reassigned to a new route from Monetta to Leesville
SC 26: extended over SC 412 from Kingstree to what is now SC 377 and over SC 44 from there to Georgetown
SC 27: transferred to SC 19 from Trenton to Aiken and US 78 from Aiken to Dorchester; reused on a new route from SC 65 (now SC 61) in Givhans to US 78/SC 2 northeast of Ridgeville.
SC 28: extended over part of SC 1 from Allendale to Yemassee, then following US 21, and extended over part of SC 30 from Yemassee to Beaufort
SC 30: truncated; transferred to US 17 from Walterboro to Yemassee and SC 28 from Yemassee to Beaufort
SC 41: transferred to US 17 from Goose Creek to Florence and US 601 from Florence to Cheraw
SC 44: transferred to SC 261 from Lane to what is now US 521 and SC 26 from there to Georgetown; reassigned to a new route from Manville to the Lee-Sumter County Line
SC 50: transferred to US 1 from Columbia to North Carolina
SC 73: renumbered SC 211 because it no longer intersected SC 7
SC 121: transferred to SC 215 from Aiken to West Columbia because it no longer intersected SC 12
SC 161: transferred to SC 215 from Columbia to Union because it no longer intersected SC 16
SC 175: replaced SC 411
SC 178: replaced SC 413
SC 211: renumbered SC 284 because it no longer intersected SC 21; reassigned as a renumbering of SC 73
SC 215: replaced SC 121 from Aiken to West Columbia, overlapped SC 2/US 76 into Columbia, and replaced SC 161 from Columbia to Union
SC 261: extended over SC 44 from Lane to what is now US 521
SC 284: replaced SC 211 to match North Carolina
SC 301: transferred to US 21 from Yemasee to Ruffin; reused on a route from Timmonsville to Lees Crossroads south of Hartsville
SC 411: renumbered SC 175 because it no longer intersected SC 41
SC 412: became part of SC 26 because it no longer intersected SC 41
SC 413: renumbered SC 178 because it no longer intersected SC 41
SC 414: renumbered SC 763 because it no longer intersected SC 41
SC 763: replaced SC 414
1929 changes (part of the renumbering? if not, did SC 25 remain one more year or was it renumbered to SC 41 or SC 50?):
SC 6: transferred to SC 24 from North to Orangeburg, rerouted over part of SC 24 from North to Olar
SC 15: truncated; section from Honea Path to Clemson transferred to SC 24; extended following SC 10 to Watts Mill, then northeast on new route to SC 92 near Cross Anchor
SC 24: transferred to SC 6 from North to Olar, rerouted over SC 6 from North to Orangeburg, Section from Ninety Six to Friendship renumbered SC 246; rerouted over SC 55 from Ninety Six to Greenwood, following US 25 to Hodges, replacing SC 25 to Donalds, followed SC 20 to Honea Path, and replaced SC 15 through Anderson and Pendleton to Clemson, and followed SC 2 to Georgia
SC 25: transferred to SC 24 from Hodges to Donalds
SC 55: transferred to SC 24 from Ninety Six to Greenwood; reused on a route from Kings Creek to Nany Mountain
SC 151: renumbered SC 248 because it no longer intersected SC 15
SC 152: renumbered SC 247 because it no longer intersected SC 15
SC 245: new route
SC 246: replaced part of SC 24 from Ninety Six to Friendship