Confederate-Mexican War over Texas (The United Confederate States of America)

Prelude (Early 1873)
In January, the Mexican Empire sent peacefull diplomats to the Confederate capital of Richmond. There, they argued that since Texas was no longer a part of the US, it belonged to them. The aging Confederate president Robert E. Lee firmly protested that Texas was theirs by right of conquest. The diplomats argued for two days reaching no concensus. So, they returned to their country. Two weeks later the Confederate forts of Rio Bravo and Del Rio, were attacked by the Mexican Army.