with US 321/SC 9. This concurrency runs southeast until US 321 branches off to the south at the southern terminus of US 321 Business (US 321 Bus.). The routes continue to the east along SC 97, running beneath a railroad bridge, and then turning toward the north. SC 9 makes a right turn at Lancaster Avenue, which is the eastern terminus of SC 9 Bus. SC 121/72/97 has an at-grade crossing with another railroad line leading to the city, and then SC 121/72 branches off to the right at Saluda Road (SC 72 Bus.), while SC 97 continues north. The concurrency with SC 72 finally ends at SC 901 in Rock Hill. Within the city, it joins briefly with SC 5, before merging with its final concurrency, US 21. Traversing east of the downtown area, its journey ends at Cherry Road, where US 21 continues north towards Fort Mill, while also connecting with SC 322. SC 121 is one of the most concurrent state highways in South Carolina. It shares long stretches of pavement with these two routes: US 25 from the Georgia state line to Trenton (20 miles) SC 72 from Whitmire to Rock Hill (46 miles, as well as the longest concurrency in South Carolina) It has shorter concurrencies with US 1, 78, and 278 (altogether), SC 230, US 178, SC 39, SC 34, US 176, SC 215, US 321, SC 9, SC 97, SC 909, SC 5, and US 21. History SC 121 had two previous stints in the state before its current routing was established. The first SC 121 was established in 1925 or 1926 as a new primary routing; it traversed from SC 27 in Aiken, northeast through Wagener and Pelion, to SC 2/SC 12 in Springdale. In 1928, it was renumbered as SC 215. The second SC 121 was established in 1929 or 1930 as new primary routing; it traversed from US 21 in Branchville, east through Bowman, to SC 31 in Providence. In 1937 or 1938, SC 121 was extended along US 78 before branching off to end at SC 65; its eastern terminus was also extended to US 15. In 1940, SC 121 was extended southwest to SC 362, and east to SC 6 in Vance. In 1948, SC 121 was truncated on both ends, from US 21 to US 15; its routing to SC 61 became Farrell's Road (S-5-18). By 1952,