Colonias, which are unincorporated border settlements in the United States, have emerged in rural areas without the governance and services normally provided by local government. The expansion of colonias in the United States-Mexico border region can be traced to the rapid growth associated with the Mexican Border Industrial Program during the 1960s. This rapid population growth created a lack of affordable housing, causing new migrants in the United States to purchase rural homestead lots through a contract-for-deed program from land developers. Because of the need to keep prices affordable and the absence of effective land-use controls, these homesteads expanded into rural subdivisions, commonly called colonias, without proper infrastructure. Colonias have been identified in the four U.S. border states, with Texas having designated the majority, which numbered over 1,400 colonias in 2001. Because the region is binationally interconnected economically, politically, and socially, the phenomenon of colonias in the United States is a transborder issue.