The republic of the Río Grande was created by a constitutional convention at the Oreveña Ranch near present day Zapata on January 7, 1840. Discontented with the Mexican Centralist government's policies, some prominent Laredoans joined this Federalistic revolt. Attempting to unite with representatives from Tamaulipas, Coahuila, and Nuevo León, the newly formed government consisted of a legislative council of eight members, with Jesús Cárdenas, a Reynosa lawyer, as president, Antonio Canales, a Tamaulipas legislator, as army commander-in-chief, and Antinio Zapata, a successful mulato rancher, as chief army lieutenant. Laredo became the capital of the new republic.

Mexican general Mariano Arista moved against the Federalist, and Laredo fell to the Centralist. Zapata's men were defeated at Santa Rita de Morelos, Coahuila, upriver from Laredo. Tragically, Zapata was executed and his head was displayed as a warning. Canales retreated north to Texas to raise support, while the remnants of his army under Samuel W, Jordan reorganized at San Patricio. Jordan's army of 300 Mexicans, 140 Texans, and 80 Carrizo Indians later reoccupied Laredo but were defeated at Ciudad Victoria. On November 6, 1840, Canales capitulated at Camargo, bringing the Republic of the Río Grande, which endured 283 days, to an end. The Laredo area was the only portion of Texas to have served under seven flags.

According to local tradition, the Bartolomé García home served as the capitol building in 1840. The Mexican vernacular home was built in the 1830's and expanded in 1861 with additional front rooms. The thick walls are constructed of hand quarried limestone and sandstone (piedra te arena) rubble and filed with adobe and lime mortar. Born in Laredo, García was the son of a military captain, and a fourth generation descendent of Tomás Sánchez. He married Carmen Benavidez, and the couple raised 12 children. A prominent rancher, Bartolome served as alcalde (mayor) of Laredo for several terms between 1843 and 1863. Two of his sons, Rosendo and Julian, also served as alcaldes in later years. García family members continuously lived in the home through the 1920's.