Sadler is on U.S. Highway 82, Farm Road 901, and the tracks of the Missouri, Kansas and Texas line, twelve miles northwest of Sherman in west central Grayson County. The area was settled in 1869 by A. J. Cross, who was soon joined by other such pioneers as Zeke Hall and Jim Beach. The community proper developed around 1878, when John Sadler, a local landowner for whom the town was named, donated land for a right-of-way to entice officials of the Missouri, Kansas and Texas to extend the railroad tracks to the settlement. A post office opened in 1892. From the mid-1920s through the mid-1930s Sadler reported a population of 400; seven businesses were there by 1936. In 1956 Sadler reported 185 residents and three businesses, and from the mid-1960s through 1990 it reported a population ranging between roughly 300 and 350. By the mid-1970s the community had incorporated, and in 1990 it had an estimated population of 316. The population reached 404 in 2000.