SC 261 appears in southern Williamsburg county 1923 Auto Trails

SC 261 truncated to relocated SC 41 1926 Auto Trails

SC 261 extended around to SC 26 1930 Official

In 1931, SC 261 west was rerouted at Greeleyville to run into SC 26 very close to Wilson. The old route north of Greeleyville became part of SC 171. Today it is S-45-27, S-45-35, and unnumbered dirt road Bennett Branch Rd.
In May 1936 (SCDOT), SC 261 was assigned to a new primary route from US 15 Paxville west to the Sumter County Line.
In July 1936 (SCDOT) SC 261 was extended west with US 521 to Manning, then west as new primary routing to Paxville.
In Nov 1937 (SCDOT), a second piece of SC 261 was created as new primary routing from US 76 Stateburg south to Poinsett State Park.
In 1939, the second piece of SC 261 was extended noth as new primary routing to end at US 521 (now S-28-2) north of Rembert.
In 1940, the two pieces of SC 261 were connected.

SC 261 northern piece appears 1938 Official

SC 261 extended north to US 521 1939 Official

SC 261 made continuous 1940 Official

In 1947, SC 261 west was truncated to US 76, leaving behind S-28-11 and S-43-19. US 76 to Stateburg became part of SC 441.
In 1949, SC 261 was rerouted east of Manning, replacing US 521 to US 52 near Kingstree. Wilson to Greeleyville became part of US 521. Greeleyville to Gourdin became SC 375 and Gourdin north to US 521 became SC 377.

SC 261 rerouted Greeleyville through Wilson 1932 Official

SC 261 extended to Pinewood 1937 Official

SC 261 rerouted to Kingstree 1949 Official

Also in 1949, SC 261 was rerouted in several places between Paxville and Wedgefield. The new 261 was on existing secondary routes west of Pinewood and on new construction from Pinewood to Paxville. The old route is now Keels Rd west of Paxville; S-43-535 Sammy Swamp Rd; Calvary Church Rd. Within Pinewood, SC 261 used to use S-43-288 Fulton St loop north of Clark; S-43-621 Clark St through central Pinewood; S-43-295 Sumter St south to Fulton. S-43-808 through Fulton Crossroads to Mill Creek State Park; Milford Plantation Rd to Poinstt State Park; River Rd and Old Charleston Rds

SC 261 loops way around to Poinsett S.P. 1945 Sumter County

SC 261 much more direct 1951 Sumter County

SC 261 dips at the County line 1945 Sumter County SC 261 much more direct 1951 Sumter County

In 1950, SC 261 was re-extended north from US 76 to US 521. In the Boykin area SC 261 was placed on new construction to stay east of the railroad the entire way.

SC 261 truncated to Statesburg 1948 Official

SC 261 re-extended to US 521 1948 Official

In 1952, SC 261 was extended east with US 52 to Kingstree, then replaced SC 175 to end at SC 41-51 Hemingway.
In 1960, SC 261 was extended east to US 701 Yauhannah replacing parts of SC 51 and SC 513.

SC 261 replaces SC 175 to Hemingway 1932 Official

SC 261 extended to Yauhannah 1937 Official

In 1961, SC 261 west was extended north to its current end south of Camden, replacing part of US 521.

SC 261 original Boykin area routing 1942 Kershaw County

SC 261 straightened out in Boykin area 1952 Kershaw County

SC 261 extended over US 521 1963 Kershaw County

Improvements: SC 261 was paved from the US 52/SC 375 jct northwest to US 521 in 1932.
SC 261 was paved from Paxville to Manning in 1937.
SC 261 was paved from Lane northward in 1938.
SC 261 was paved from Paxville to the Sumter line in 1939.
SC 261 was paved from Lane southwest to US 52 in 1940.
SC 261 was paved from Pinewood east to the Clarendon line in 1941.
By 1948, SC 261 was paved from Poinsett S.P. north to US 76.
In 1949, SC 261 was paved from Poinsett S.P. to Pinewood.
All extensions of SC 261 were paved upon designation after this.
SC 261 only has 2 multilane segments:
US 52 duplex which was multilaned east of the Black River by 1975 and west of the Black River in 2000.
I-95 to Manning which is not shown on maps but has been that way back to at least the mid 1990s.
Comment: SC 261 is one of the longer 3-digit routes in South Carolina.
SC 261 serves Poinsett State Park.