Mexican Cession Mexican Cession, with considerable local autonomy punctuated by several revolts and few troops sent from central Mexico, in the period from 1821–22 after independence from Spain up through 1846 when U.S. military forces seized control of California and New Mexico on the outbreak of the Mexican–American War. The northern boundary of the 42nd parallel north was set by the Adams–Onís Treaty signed by the United States and Spain in 1821 and ratified by Mexico in 1831. The eastern boundary of the Mexican Cession was the Texas claim at the Rio Grande and extending north from the headwaters of the Jojo
Solemn Act of the Declaration of Independence of Northern America Solemn Act of the Declaration of Independence of Northern America The Solemn Act of Northern America's Declaration of Independence () is the first Mexican legal historical document which established the separation of Mexico from Spanish rule. It was signed on November 6, 1813, by the deputies of the Congress of Anáhuac, organized by General José María Morelos in the city of Oaxaca in June of that same year, and later installed in the city of Chilpancingo on September 13. The document gathers some of the main political uprisings contained in "Feelings of the Nation" ("Sentimientos de la Nación"), a document