Texas State Highway 1

In the original 1917 definition, SH 1 had a split between Abilene and Palo Pinto (west of Mineral Wells). Another split was present between Sulphur Springs and Texarkana, and a branch ran from the northern route at Naples east to State Highway 8 at Douglassville.[6] SH 1 followed State Highway 39 from Greenville to Commerce and went southeast to Sulphur Springs when the route was decided. On February 19, 1918, the southern route between Sulphur Springs and Texarkana had become State Highway 1A, and a new State Highway 1B ran from SH 1 in Naples to Douglasville, and a new State Highway 1C ran southeast from SH 1A at Atlanta to the Louisiana state line.[20] On March 20, 1918, SH 1A extended north from Texarkana north to the Red River (the Arkansas state line).[21]

The southern route between Abilene and Palo Pinto was improved first.[22] Thus it was designated as part of US 80 in 1926. The north route was redesignated on August 21, 1923, as State Highway 1A, and in 1932 was designated US 80N (later U.S. Highway 80 Alternate),[23][24][25] On March 16, 1927, SH 1 was rerouted on the direct route between Sulphur Springs and Greenville, and the old route became part of SH 39 and SH 11.[26] On August 8, 1935, all of SH 1A west of Albany was transferred to SH 15, but that was not effective until September 1 of that year.[27] On October 23, 1935, US 80 and SH 1 were rerouted onto the direct route between Ranger and Weatherford, replacing part of State Highway 89,[28][29] and US 80 Alt. was extended east to Weatherford; this did not become effective until paving on SH 89 from Strawn to Weatherford was completed. It was unknown what the old route would become, but on November 19, 1935, the section from Weatherford to Palo Pinto was already part of SH 15, and the section from Palo Pinto to Strawn would become part of an extended SH 120. The SH 1A designation was removed in the 1939 general redescription, and US 80 Alt. was replaced on September 6, 1943, by State Highway 351 and U.S. Highway 180.[30][31]

The other branches, located east of Dallas, were all renumbered on August 21, 1923:[25][32]

• The section of SH 1A from Commerce east to Daingerfield became part of State Highway 11. This road still carries SH 11. The section of SH 1A from Daingerfield to Hughes Springs became part of State Highway 49 and the section of SH 1A from Hughes Springs east to Atlanta became State Highway 48.
• SH 1B was renumbered to State Highway 77.
• SH 1C and the section of SH 1A from Atlanta north through Texarkana to the Red River became State Highway 47. On June 24, 1931, the section of SH 47 that replaced SH 1C became an extension of SH 77, and SH 47 was rerouted to Daingerfield, eliminating SH 48. On the September 26, 1939 redescription, SH 11 (which had gone north from Daingerfield) was extended east from Daingerfield along former SH 1A to the Red River, eliminating SH 47. (The short piece of SH 49 became a concurrency.) SH 11 was truncated to Linden on October 13, 1947, when the rest became part of U.S. Highway 59.[33]

A branch was designated on Commerce Street in Dallas on March 13, 1931. On November 11, 1933, it was known as SH 1B.[34] This was eliminated on September 26, 1939. Another SH 1C was designated on Lancaster Street on March 17, 1936.[35] This was eliminated on September 26, 1939 (became US 80).