Republic of the Rio Grande (U.S.):
"I spotted this flag in Laredo while traveling in south Texas. I was curious about its resemblance to the Texas state flag, so I did some research to determine its origins.
The red, black and white flag was the national flag of the short-lived Republic of the Rio Grande. A group of rebels known as the Federalists declared a republic based on the Mexican Constitution of 1824. The new state was to include the Mexican States of Coahuila, Nuevo Leon and Tamulipas, with its capital at Laredo. The Republic of the Rio Grande was declared in January 1840.
The Centrists in Mexico City (who were responsible for the suspension of the 1824 constitution) moved to quickly bring the Rio Grande back into the fold. Laredo was captured by Mexican forces less than two months later, but the insurgency continued and the Federalists eventually retook the town. A major Centrist victory at Satillo in October 1840 effectively killed the Republic of the Rio Grande. The Federalists surrendered two weeks later and their new nation ceased to exist. The republic lasted 283 days.
Although the republic is long gone, its flag is still displayed in prominent places, including the masthead of the local paper."
Ryan Fennell, 27 July 2000