The history of the counties in Texas is a long and complex one, with the boundaries of existing municipalities changing over time. After the establishment of the Republic of Texas and its new government following the revolution against Mexico, the boundaries of existing municipalities as new counties were vague and not well defined. At least 32 counties established by Texas law no longer exist, since they disappeared due to changes in the Texas constitution, and were eliminated because of their designation as judicial counties or because of political party disputes during the Reconstruction after the Civil War. During the colonial period in Texas, the Spanish and, later, Mexican governments issued vast land concessions for businessmen to allow settlement in Texas.
The Texas Constitution of 1836 specified that the republic would be divided into counties as necessary and that any new county created by the Texas Congress would require the petition of one hundred free men and would have to cover a minimum of 900 square miles. In some cases, the Republic or later the State of Texas imposed the name of the new county, while in others, no one knows with certainty how the county got its name. The rules changed once again after Texas became a state in 1845, when the new Texas Constitution stipulated that no existing county could be reduced to less than 900 square miles without the consent of a two-thirds majority of the Legislature. In addition, this document contains many other provisions that empower or prohibit the actions of county government.
Under the Republic of Texas, these municipalities became counties, at which time their governmental structure changed to resemble the organization of counties in other southern states. In practical terms, the sparse and mostly rural population of Texas in the first few decades after independence from Spain made counties the natural components of local government. Counties formed from those already organized had to be at least 700 square miles in size and no parent county could be reduced to less than that minimum. Brewster County in West Texas is currently the largest at 5,935 square miles, three times the size of Delaware and more than 500 square miles larger than Connecticut.
The counties of Texas have their lineage in the Spanish municipality, a word that is not directly translated into English. That would mean that the average population per county (counting Native Americans) was less than 2,200 people in the twenty-three Spanish municipalities that became counties after independence. In 1876, a new Texas Constitution stated that new counties of less than 900 square miles could not be formed from unorganized land, and that these counties should be as square as possible. Rockwall County was created from Kaufman County in 1873 due to poor access to the former seat of Kaufman County and is currently the smallest county in Texas, with 149 square miles.
