US troops occupied the Mexican border town of Matamoros from 1846 to 1848 during the Mexican-American War. The troops were not welcome, but no serious confrontations occurred. American merchants established stores, restaurants, hotels, and other businesses in the town. After the occupation, the army moved to the north side of the Rio Grande and founded a new community called Brownsville. The occupation helped develop the social and commercial relationship between Matamoros and the Texas town of Brownsville.
Mills, J. W. (2007). The United States Military Occupation of Matamoros, Mexico, 1846 - 1848. Journal of South Texas, 20(2), 268–279.
Journal of South Texas