On April 11, 1846, Limestone County was formed from Robertson County, and a week later Springfield was established as the county seat. This town had a population of 120 when it was incorporated in 1848. In 1873, however, when the courthouse burned and the Houston and Texas Central Railway bypassed the town, an election was ordered and Groesbeck became the county seat. The organization of the county was completed on August 18, 1846, with the election of county officials. Limestone County originally included all the land between the Brazos and Trinity rivers on the east and west, and the land north of Robertson County to Navarro County. In 1848 part of northern and western Limestone County was taken to form McLennan and Falls counties, and in 1850 part of the eastern section was taken to form part of Freestone County. The boundaries were changed to their present form on November 2, 1866. -Handbook of Texas Online: Limestone County