From east to west, the border consisted of the Rio Grande northwest from its mouth to the point where it strikes the southern boundary of New Mexico roughly 32 degrees northas shown in the Disturnell mapthen due west from this point to the th meridian westthen north along the th Meridian to the Gila River and down the river to its mouth.
The Mexican government, headed by the ad interim Mexican president Manuel de la Pena y Pena, quickly agreed to the boundary issues: Texas's southern boundary would be the Rio Grande, the cession of Alta California would include the port of San Diego, and Mexico would give up its territory between Texas and California, with a boundary to be surveyed.
The remainder the southern parts of New Mexico and Arizona were peacefully purchased under the Gadsden Purchasewhich was carried out in British efforts to mediate the quandary proved fruitless, in part because additional political disputes particularly the Oregon boundary dispute arose between Great Britain as the claimant of modern Canada and the United States.
The treaty added an additionalsquare miles to United States territory, including the land that makes up all or parts of present-day ArizonaCalifornia, ColoradoNevadaNew Mexico, Utah and Wyoming.
Changes to the treaty and ratification[ edit ] The version of the treaty ratified by the United States Senate eliminated Article X,  which stated that the U.
Negotiations began in earnest in January Nor shall any tax or contribution, under any denomination or title, be levied upon vessels or persons navigating the same or upon merchandise or effects transported thereon, except in the case of landing upon one of their shores.
An amendment by Jefferson Davis giving the U.