The Clinchfield was the last Class 1 railroad to be built east of the Mississippi. It opened in 1915, linking Spartensburg, SC with Elkhorn City, KY. It went from the extreme southeast corner of Kentucky, through the western tip of Virginia, eastern tip of Tennessee, the western tip of North Carolina, and into the northwest corner of South Carolina. No railroad that served five states was shorter than the Clinchfield. In 1924, the Atlantic Coast Line and the L&N leased the railroad. The Clinchfield maintained a separate identity up to the mid 1970s, when it was folded into the Family Lines, which morphed into the Seaboard System then into CSX.

During the increased war-time traffic of the early 1940s, the Clinchfield Railroad needed more locomotives. They ordered eight single-expansion 4-6-6-4s from the American Locomotive Company and took delivery of them in 1942 and 1943. They were similar to the D&H Class J "Challengers" built in 1940. These locomotives were designated Class E-1 and were assigned road numbers 650 though 657. They had (4) 22 x 32 cylinders, 69" drivers, a boiler pressure of 265 psi, exerted 101,000 lbs of tractive effort and weighed 607,000 pounds.

After the war in 1947, four more "Challengers" were received from ALCO. This group was designated Class E-2 and given road numbers 660 through 663. These locomotives were very similar to the Class E-1s.

There were six other "Challengers" received by the Clinchfield. The D&RGW did not like the six ALCO built 4-6-6-4s they received through the War Production Board in 1943. They preferred the locomotives they had purchased from the Baldwin Locomotive Works. The D&RGW sold the six Alco-built "Challengers" to the Clinchfield in 1947. This group was designated Class E-3 and were given road numbers 670 through 675.

All 18 of the Clitchfield "Challengers" were scrapped in 1953 and 1954.

In November of 1992, to help the City of Kingsport, TN and CSX celebrate the 50th anniversary of the running of the Santa Train from Elkhorn City, KY to Kingsport, Union Pacific brought their Challenger in, renumbered and relettered it to be Clichfield 676.