https://en.wikipedia.org/wiki/Republic_of_the_Rio_Grande
It's now a restaurant in central McAllen.

I recommend te Ribeye Chicharrones; they're to die for!
https://www.therepublicmcallen.com/
Forget the history. Remember the food!
The story of an independent republic that was declared and fought over 10 months of 1840 started long before, during the social turmoil that embroiled Mexico and its vast geographical domain. Coming out of a valiant and victorious struggle for independence in 1821, against the 300 year rule of the Spanish Empire, Mexico adopted the constitution of 1824, which favored a federalist form of government. Almost immediately, an independent movement began the northern providence of Texas. This Texan separatist faction based their secession on the change from the federalist form of government in Mexico to a centralist one in 1836.
On November 5, 1838, Antonio Canales of Monterrey issued a proclamation calling for the re-adoption of the federalist constitution of 1824. By 1839, the citizens of Laredo had joined the case. Helped by the French blockade of Mexican ports, the federalists were able to capture several towns. By March, however, the French lifted their blockade, allowing the centralists to devote more resources to fight the federalists.
Between May and September 1839, Centralists captured Saltillo, Tampico, Monclova and Laredo. Antonio Canales and his Chief Lieutenant, Antonio Zapata, retreated on the Nueces River and sought the support of the president of Texas, Mirabeau Lamar.
In 1839, Laredo was taken back by the Federalists. By January 7th , 1840, the Republic of the Rio Grande was proclaimed by constitutional convention, and Laredo was named its capitol. On the 17th of that same month, Jesus Cardenas, a lawyer from Reynosa, was chosen president. Jose Maria Jesus Carbajal was appointed to represent the Republic of the Rio Grande in Texas, and enlist recruits for the army. Antonio Canales was named commander in chief .of the army, and Colonel Antonio Zapata served as commander of the calvary.
Almost immediately, the Republics forces embarked on a series of battles with Centralist forces, taking, losing and re-taking various villas along the Rio Grande, and even further south into Mexico. After a disastrous defeat at Santa Rita de Morelosin Coahulia (
in which Camales role was later described as cowardly and militarily inept) Federalist survivors of the battle were court-martialed, found guilty of treason, and shot. Zapatas head was cut off, preserved in a cask of brandy, and returned to his hometown of Guerrero, where it was displayed on a pike for 3 days as a warning to others.
Sarcasm over the history. The food is for real. Seriously.
NO, really!