The Flag of the Republic of the Rio Grande was used in 1840, during 283 days from January 17 to November 6, as long as the republic existed. This country was formed by the northeastern Mexican states of Coahuila, Nuevo León, and Tamaulipas.
The flag of the Republic of the Rio Grande has a red hoist with three white stars run evenly along the hoist. The three stars represent the three states that seceded: Coahuila, Nuevo León, and Tamaulipas. The fly is split into a white upper fly and a black lower fly. It was purposefully designed similar to the Lone Star Flag as the Republic of the Rio Grande was fighting for the same ideals as the Republic of Texas was.
Recently, there has been some debate as to the original colors of the flag, especially the color of the stripe on the lower fly. It has always been assumed that the lower stripe is black. However, some sources say that the original color of the lower stripe may have been green, but because of time and poor storage conditions has turned to black.. In addition, according to some Texan historians the lower stripe of the original flag was blue and was captured by the Mexican army.
The city of Laredo, Texas uses the flag as their city flag.