In 1830 the territory of what would become the county was incorporated into the new Viesca District, and in 1835 it became part of the newly organized Washington Municipality. The first post office in the area was established in December 1835 at the Fanthorp Inn. It became part of Montgomery County, which was organized by the Congress of the Republic of Texas in 1837. On April 6, 1846, the first state legislature accepted the petition of local residents and established Grimes County, named in honor of Jesse Grimes, a signer of the Texas Declaration of Independence who was then representing the area in the state Senate. A vigorously contested election later in the year resulted in the designation of Anderson-recently platted in the center of the county-as the seat of government. In 1853 Madison County was carved out of northern Grimes County, which assumed its present boundaries in 1873, when Waller County was formed from territory in its southern extremity. -Handbook of Texas Online: Grimes County