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 designed to be 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.
The city of Laredo, Texas uses the flag as their city flag.