Farmersville originated in 1849 as a settlement on the Jefferson-McKinney Road, and near Republic of Texas National Road. Named by pioneers for their chief occupation. After 1854, the Yearys and their neighbors of Sugar Hill (2 mi. NE) began relocating here. Dr. H.M. Markham, practicing here by 1855, is said to have been Collin County’s earliest physician. The first Methodist Church was organized in 1856. William Gotcher on March 4, 1859, donated land for the public square. A school was operating as early as the 1860s. The first Baptist Church was organized on May 14, 1865.
Institutions of 1880s still in operation include Farmersville "Times" and the First National Bank, as well as the two churches mentioned above.
As town became a trade center, agriculture kept pace. Farmersville in 1930s was known as the "Onion Capital of North Texas", annually shipping over 1,000 carloads of onions. Along with some small industry, cattle cotton, and maize crops remain important.