Vail's Mill was the basis for Middletown. The town was platted Nov. 1, 1802, by Stephen Vail, who also built a mill there in 1802. Vail, a native of New Jersey, came to the area in 1800. According to the 1882 history, "soon after he came he purchased a large tract of land lying on both sides of the Miami River, and commenced the erection of mills, consisting of a gristmill, a fulling mill and a saw mill. These mills were finished and in use in 1802. A destructive freshet in 1805 carried away or greatly damaged the fulling mill and the saw mill. The fulling mill was rebuilt the next year." Vail died in 1808.