US 15 and 21 in South Carolina

By | October 18, 2022

US 15 in South Carolina

US 15
Get started Walterboro
End McColl
Length 159 mi
Length 255 km
Walterboro alto

St. George

Holly Hill






Society Hill


North Carolina

US 15 is a US Highway in the US state of South Carolina. The road forms a north-south route through the east of the state, from Walterboro through Sumter to the North Carolina border. US 15 is 255 kilometers long in South Carolina.

  • ElectronicsMatter: State facts of South Carolina, covering history, geography, demography, economics, politics, and administrative division of South Carolina.

Travel directions

US 15 is a mostly two-lane north-south route through the east of the state. US 15 begins in Walterboro on the US 17 alternate. US 15 first follows Interstate 95 in South Carolina to Summerton, then follows its own corridor through Sumter, Hartsville, and Bennettsville to the North Carolina border. Due to the many US Highways in this area, US 15 is not a dominant route, and it also runs parallel to I-95 north of Sumter. US 15 in North Carolina continues toward Fayetteville.


US 15 was one of the original US Highways of 1926, but it did not yet run through South Carolina at the time. This was the case from 1935, when the southern starting point was changed from Rockingham, North Carolina to Walterboro, South Carolina.

  • Fun-wiki: Brief information of the state South Carolina, covering basic history and geography as well as top cities of South Carolina.

The first bridge over Lake Marion was built in 1946. The 1.6-kilometer-long bridge was decommissioned in 2018, US 15 has since been routed over the adjacent bridge of Interstate 95. The bridge was subsequently demolished. In the 1950s, a short section of US 15 on the north side of Walterboro was widened to 4 lanes. The road was also moved outside the center of Bennettsville in the north of the state in the 1950s.

Interstate 95 was built parallel to the southern portion of US 15 during the 1960s, so this route was not upgraded further. In the early 1970s, the southern approach road from Sumter was widened to 2×2 lanes. Sumter is also the largest town on the route, but has no bypass for US 15 traffic. The rest of the route has not been directly replaced by highways, but does not serve any larger cities except Sumter.

US 21 in South Carolina

US 21
Get started Hunting Island
End Fort Mill
Length 233 mi
Length 375 km
Hunting Island






Great Falls

Fort Lawn

Rock Hill

Fort Mill

North Carolina

US 21 is a US Highway in the US state of South Carolina. The road forms a north-south route through the center of the state, from Hunting Island through the capital Columbia to the border with North Carolina. US 21 is 375 kilometers long in South Carolina.

Travel directions

Coastal area around Beaufort

US 21 begins in Hunting Island, a barrier island on the Atlantic Ocean. The road then follows a route over a series of other islands to Beaufort, this part has several bridges, including some larger bridges. Beaufort is located on peninsulas and surrounded by tidal rivers and swamps. From Beaufort, the road has four lanes, partly as a 2×2 divided highway and partly as a five-lane road with a center turn lane. The swampy area extends quite far inland and the road also has several bridges north of Beaufort. In rural areas north of the city is a short double numbering with US 17.

Inland to Columbia

The road then heads inland as a single carriageway through wooded areas. After Yemassee you cross the Interstate 95. The US 21 then leads through a relatively sparsely populated region, with few places of significance as far as Orangeburg. The road here is a quiet single carriageway, except for the last few kilometers into Orangeburg, which has 2×2 lanes. The road then runs right through the city of Orangeburg and intersects with US 178. North of Orangeburg the road is single lane again, Interstate 26 runs parallel to US 21. South of Columbia one also crosses I-26 three times.

Columbia – North Carolina

US 21 then crosses the capital Columbia. US 21 runs off the grid through Downtown Columbia and also crosses the Congaree River there. In Columbia you cross US 1, US 176, US 321 and US 378. North of Columbia is also a connection to Interstate 20.

US 21 then follows a route north that remains somewhat outside the suburbs of Columbia. Interstate 77 runs parallel to US 21 here. US 21 also parallels the Catawba River through an area of ​​fairly dense forest and few sites of significance until closer to the North Carolina border. US 21 passes through the small town of Rock Hill here, but remains outside the center. Around Rock Hill, US 21 is partially equipped with 2×2 lanes. At Rock Hill, it crosses I-77 twice, then US 21 merges onto I-77 at the last junction before the North Carolina border and continues through the city of Charlotte.


US 21 was one of the original US Highways of 1926, the original starting point was US 17 in Yemassee. In 1935 the southern terminus was changed to Beaufort and in 1953 to nearby Hunting Island.

At the time, US 21 was one of South Carolina’s main highways, connecting Savannah, Columbia, and Charlotte. It was also one of the few US Highways that actually ran north-south, as most US Highways in South Carolina are more tilted from their usual grid position.

In the 1950s, a small section of US 21 as a southern approach road from Columbia was widened to 4 lanes. In the early 1960s, the section through Beaufort was also widened to 4 lanes, as was the northern approach road from Rock Hill in the north of the state. In the early 1970s, US 21 was also widened to 2×2 lanes about 15 miles south of Rock Hill. At that time, I-95/I-26 was already ready between Yemassee and Columbia, so few upgrades were made to the southern part of US 21. Due to the construction of I-77 north of Columbia in the mid-to-late 1970s, US 21 has undergone little upgrade there, even closer to Columbia.

On April 26, 2021, a new high and fixed bridge opened in Beaufort County over the Harbor River in the outer coastal area and near the end of US 21.

US 21 in South Carolina