sentences:  The route was extended southward from Colorado to the Gulf Coast at Port Arthur, Texas in 1939.Before this extension, the portion from the Oklahoma state line to Amarillo was SH 9, from Amarillo to Henrietta was SH 5, Henrietta to Bowie was SH 50, Bowie to Fort Worth was SH 2 and US 81, Fort Worth to Ennis SH 34, Ennis to Corsicana was SH 14/US 75, Corsicana to Palestine was SH 22, Palestine to Crockett was SH 19, Crockett and Woodville was Texas State Highway 106, Woodville to Port Arthur was SH 8.From 1926 to 1939, the aforementioned state routes between US 66 in Claude and US 81 in Bowie were co-designated with U.S. Route 370, which was commissioned in 1926.