SC 18 Westminster to Walhalla 1924 Blue Book

SC 183 from Westminster to Walhalla 1926 Official

Adjustments: About 1929, SC 183 was extended east as new primary routing through Pickens to end at SC 284 (now US 276) Marietta.
In 1936 or 1937, SC 183 was rerouted above Pickens to instead end at US 276 south of Caesars Head. The old route to Marietta was secondary for a little while before becoming SC 186.

SC 183 extended to Marietta 1930 Official

SC 183 rerouted towards Caesars Head 1937 Official

In 1939, SC 183 was extended west with US 76, then west as new primary routing to end at the Georgia State line (across from today's GA 184).
In 1947, SC 183 west was truncated to US 76-123 Westminster, leaving behind S-37-17 (today this is S-37-34 and S-37-160).

SC 183 extended to Georgia 1939 Official

SC 183 truncated back to Westminster 1948 Official

In 1956, SC 183 was rerouted at Pickens to head east to Greenville, replacing SC 416. Note that a lot of SC 183 was put on new construction as SC 416 used a convoluted routing. The old SC 183 routing north to US 276 became part of SC 8. SC 183 originally ended at US 29 Main St in Greenville.

SC 416 from Pickens to Greenville 1949 Official

SC 183 rerouted to Greenville 1956 Official

SC 416 convoluted routing in Pickens County
1953 Pickens County

SC 416 replaced by a much more efficient SC 183 routing
1959 Pickens County

SC 183 preparing for Lake Keowee 1969 Oconee County

SC 183 rerouted 1974 Oconee County

Improvements: SC 183 was paved between Walhalla and Westminster by 1932.
In 1933, SC 183 was paved from Pickens west to the Seneca River Bridge.
In 1937, SC 183 was paved 5 miles east out of Pickens and from Walhalla to today's SC 188
In 1939, SC 183 was paved from Westminster to Pumpkintown.
In 1941, SC 183 was paved from Pumpkintown north to US 276.
All parts of SC 183 have been paved since 1947.
In 1964, SC 183 was 4-laned from just west of today's SC 253 into central Greenville.
In 1970, the 4-laning was extended west to US 25.
In 1971, the 4-laning was extended a little futher west of US 25.
SC 183 is multilane within the town of Pickens, and I think it was that way in the late 1980s.
Comment: SC 183 is poorly posted in downtown Greenville and is posted in a way that suggests it ends at US 123.
SC 183 serves the Oconee Nuclear Station, as well as provides a route across central Oconee and Pickens Counties.
The old SC 183 at the Georgia State Line passed over one of South Carolina's few covered bridges to make it to modern times, the Prather Bridge, which was burned down in 1978.