Territorial evolution of Mexico

One such decree was the Law of Bases for the Convocation of the Constituent Congress to the Constitutive Act of the Mexican Federation, which determined the national land area as the result of integration of the jurisdictions that corresponded to New Spain, the Captaincy General of Yucatán, the Captaincy General of Guatemala and the autonomous Kingdoms of East and West.

The liberal government of Antonio López de Santa Anna, influenced by conservatives, ratified the Seven Laws by presidential decree, establishing a new territorial court and replacing the federal states by departments whose governors and legislators would be selected by the President.

Territorial divisions throughout Mexican history were generally linked to political change and programs aimed at improving the administrative, country's economic and social development.

The reorganization was accomplished by Manuel Orozco y Berra (1816–1881), and was made according to the following rules: This division was of great importance, because geographical features and projected development were taken into account for the delimitation of the jurisdictions.

The list of acts is not affected by this confusion, but the associated maps contain the following uncertainties and omissions: Some of the borders of states in the north, and in northeast Texas, before independence and the Mexican Cession After the end of the empire, the Central American provinces decided not to be part of Mexico.

Including Texas, Mexico ceded an area of approximately 2,500,000 square kilometres (970,000 sq mi) – by its terms, around 55% of its former national territory.

Mexican people angered by the sale proclaimed the Plan of Ayutla, which finally ended the political career of Santa Anna.

The South Territory of Baja California and the Quintana Roo Territory were admitted as the states of: The Banco Convention of 1905 resulted in many exchanges of bancos (land surrounded by bends in the river that became segregated from either country by a cutoff, often due to rapid accretion or avulsion of the alluvial channel) between the two nations, most often in the Lower Rio Grande Valley.

Under the treaty, the following transfers involving Texas occurred from 1910 – 1976:[23] In 1927 under the same 1905 Convention, the U.S. acquired two bancos from Mexico at the Colorado River border with Arizona.

The Rio Grande Rectification Treaty of 1933 straightened and stabilized the 155 miles (249 km) of river boundary through the highly developed El Paso-Juárez Valley.

The Chamizal Treaty of 1963, which ended a hundred-year dispute between the two countries near El Paso, Texas, transferred 630 acres (2.5 km2) from the U.S. to Mexico in 1967.

The Boundary Treaty of 1970 transferred 823 acres (3.33 km2) of Mexican territory to the U.S., in areas near Presidio and Hidalgo, Texas, to build flood control channels.

This period created a great political instability that began in regional problems and conflicts between the central entity and the states of the country.

It provided the legal basis for governing the country in the period between the Plan of Ayutla and Federal Constitution of the United Mexican States of 1857.