It may never have included more than a few houses when it was said to have been founded in the late nineteenth century. Henry Wetsel, a prominent McKinneymerchant and early settler, is honored by the community's name. Wetsel eventually sold his holdings in McKinney and headrighted a square mile of land south of the town. Wetsel had built and run an early grist and flour mill in the county seat. On the stageroute that connected Austin and McKinney, he built a cottage. Allen now includes the former Wetsel area.