A copy of that legal, binding treaty must either still exist or there must be a record of it.
I'd like to see them try to dispute a legal document.
Oh wait, what am I saying? They have no respect for the law and so would have no respect for a binding legal document.
(And they want us to respect them??)
I'd like to see them try to dispute a legal document That and negating "Manifest Destiny" is all their warped brains can think about. It was a great insult to the strutting, preening and ridiculously proud Spaniards, er, Mexicans that the new kids in the Americas dumped them so quickly and decisively. They just haven't gotten over it.
Search on Reyes Tijerina and Treaty of Guadalupe Hidalgo for some of the beginnings of the current insurrection.
I haven't had a chance to do anything more than glance at it but this might be what you were looking for:
TREATY WITH MEXICO (February 2, 1848)
[By the Louisiana Purchase, Texas had become a part of the United States; but in 1819 it had been ceded to Spain in the negotiations for Florida. Two years later Mexico, including Texas, had become independent, and the United States made two unsuccessful attempts to purchase Texas from Mexico. The settlement of Texas by immigrants from the United States finally led to the secession of Texas and its annexation by the United States, with the result that the Mexican War broke out in May, 1846. It was closed by this treaty, by which the United States gained not only Texas but New Mexico and Upper California.]
TREATY OF PEACE, FRIENDSHIP, LIMITS, AND SETTLEMENT BETWEEN THE UNITED STATES OF AMERICA AND THE UNITED MEXICAN STATES CONCLUDED AT GUADALUPE HIDALGO, FEBRUARY 2, 1848; RATIFICATION ADVISED BY SENATE, WITH AMENDMENTS, MARCH 10, 1848; RATIFIED BY PRESIDENT, MARCH 16, 1848; RATIFICATIONS EXCHANGED AT QUERETARO, MAY 30, 1848; PROCLAIMED, JULY 4, 1848.
cont'd......
http://www.azteca.net/aztec/guadhida.html