HEMPSTEAD, TEXAS. Hempstead, the county seat of Waller County, is on U.S. Highway 290 at its junction with State highways 6 and 159, fifty miles northwest of Houston. Dr. Richard Rodgers Peeblesqv and James W. McDade, founders of Hempstead, organized the Hempstead Town Company on December 29, 1856, to sell lots in the new town at the terminus of the projected Houston and Texas Central Railway. The doctor named the town for his brother-in-law, Dr. G. S. B. Hempstead of Portsmouth, Ohio.
The Houston and Texas Central was extended to Hempstead on June 29, 1858, and the town became a distribution center between the Texas interior and the Gulf Coast. Hempstead incorporated on November 10, 1858, and its importance as a transportation center increased with construction of the Washington County Railroad from Hempstead to Brenham.
Above information from the Handbook of Texas Online.