The War ended with the signing of the Treaty of Guadalupe Hidalgo, which gave Mexican citizens one year to choose U.S. or Mexican citizenship. The Fourteenth Amendment (Amendment XIV) to the United States Constitution was adopted on July 9, 1868, as one of the Reconstruction Amendments.A) The parties agree to extend the term of the contract for three months, in the period comprehended between January 1 to March 31, 2018. As enacted, the Fourteenth Amendment confers substantive rights against the States which, like the provisions of the Bill of Rights, are self-executing. Cf. House, Representative John Bingham urged that "you must amend the. We must look to see if the interest is within the Fourteenth Amendment's protection of liberty and property. This treaty, signed on February 2, 1848, ended the war between the United States and Mexico. By its terms, Mexico ceded 55 percent of its territory. Col of Amendment to that Agreement, done at Mexico City on. Many analysts believe that Mexican.