SH 19 was one of the original 25 Texas state highways proposed on June 21, 1917, overlaid on top of the
Paris-Houston Highway. The original proposal was for it to run from the Texas/Oklahoma border north of Paris to Houston. On February 5, 1918, it was extended south to Freeport. On August 21, 1923, SH 19 was pared back significantly, eliminating the section north of Grand Saline. On August 4, 1932, it had extended north to Alba. On May 13, 1935, it was rerouted to end in Fruitvale. On September 4, 1935, an eventual extension via Emory, Commerce, Ladonia, and Bonham to Oklahoma was proposed. On August 1, 1936, the section from Canton to Grand Saline was restored as
SH 19T. SH 19T was cancelled when the rerouting of SH 19 from Canton to Fruitvale opened. On September 26, 1939, the sections south of Palestine which were cosigned with
US 287 and
US 75 were dropped. One section became part of
SH 45 (now
SH 30), and another was renumbered to
SH 288. On April 15, 1940, SH 19 was extended north to Sulphur Springs, a modification of the much longer proposed extension that was not designated. On September 26, 1945, SH 19 was routed over
FM 647 from 1 mile south of the Hopkins County line through Emory to Dunbar. On August 24, 1960, it was extended northward to its original starting point of Paris and again to the south to Huntsville, replacing a portion of SH 45. On May 21, 1979, SH 19 was extended over Loop 405 in Huntsville.
SH 19A was a spur route of SH 19 that was originally planned on February 18, 1919, splitting off at
Angleton and traveling to
Palacios. On March 19, 1923, it was extended east to
Galveston and west to
Ganado, with the old route to Palacios being changed to SH 19B. On August 21, 1923, the route had been renumbered as
SH 58 (now
SH 35).
SH 19B was a spur route of SH 19 that was originally planned on March 19, 1923, from
Midfield to Palacios replacing part of rerouted SH 19A. On August 21, 1923, the route had been renumbered as
SH 59. ==Junction list==