What border did both mexico and the united states claim as their own?

The answer is Texas. Battle with Mexico started when the United States seized Texas as a state in 1845. Mexico appealed that the new border between Texas and Mexico was the Nueces River, while the United States challenged the border was the Rio Grande. Fighting started when an objectivity of U.S. help was criticized near the Rio Grande.

britain's king george iii, however, refused to receive the petition, which, written we consider whom we must oppose in this contest, and if it continues, what may the fundamental grounds upon which americans were taking up arms had shifted. that king george refused to so much as receive the