All-Mexico Movement

Manifest Destiny Unleashed
1845-48

In 1845, tensions between the United States and Mexico reached a boiling point, driven by the doctrine of Manifest Destiny and the belief that the U.S. was destined to stretch from coast to coast.

Polk’s administration was eager to expand American territory, especially into the fertile lands of Northern Mexico and California. After Texas (a former Mexican state), joined the U.S., the Mexican-American War erupted.

Unfortunately for Mexico, American settlers in Alta California overthrew the costal government and declared the Bear Flag Republic. Meanwhile, U.S. forces quickly gained ground down the coast of the Mexican gulf.

By ’48, the government in Mexico City was toppled by U.S. force. Back in Washington, the All-Mexico movement – pushing for the full annexation of Mexico, was steadily gaining popular support.

Bargaining for a southern border beginning in Tampico, up the river to a parallel through the Tropic of Cancer – the Treaty of Guadalupe Hidalgo was signed in 1848.

A Nation Divided
1848-49

After 1848, the newly annexed territories were divided into regions like Northern Mexico and Nuevo Mexico. Resistance was fierce, especially in the southern regions.

The U.S. government faced guerrilla warfare and political instability – especially along the new southern border, as disparate Mexican forces continued to fight for their independence.

After several particularly large attacks on U.S. troops stationed in Rio Grande – Polk’s administration saw an opportunity to solidify control by occupying the strategic port of Vera Cruz, pushing the U.S. military deeper into Mexican territory. Expectedly, this was met with fierce resistance, and what had been a loose peace, now once again erupted into war.

Meanwhile, 1849 – the threat of an invasion by Guatemala prompted representatives to petition for U.S. statehood, which was quickly granted. Unfortunately, but the time things were organized, Guatemala had invaded, prompting military action in the Gulf of Honduras.

The War Continues
1849-51

The ongoing guerrilla warfare made integration of the new northern Mexican territory difficult. As a result, the New Mexico territory was greatly expanded and more federal resources poured in.

The war in southern Mexico was winding down, with the largest contenders in the shattered Mexican state cut off from each other. But the fighting in the uncaptured regions remained just as fierce as ever.

With help from newly minted Central American states, the U.S. was quick to crush and drive the Guatemalan armed forces into the mountains and rainforests.

Chaos and Rebellion
Across Mexico
1851-59

By the end of the 1850s, the United States had entrenched itself in much of Mexico, but peace remained elusive. The occupation was characterized by martial law, as U.S. forces struggled to maintain order in the face of persistent guerrilla warfare by Mexican rebels. Major cities like Mexico City, Acapulco, and Guatemala City were under American control, but the countryside remained volatile.

During this decade, the population regions in Southern Mexico were governed by the U.S. military while the guerrilla conflict raged.

The Confederacy’s Folly
1859-62

The outbreak of the American Civil War in 1861 added a new layer of complexity to the situation in Mexico. The creation of the Confederate States of America infuriated Washington, which declared war shortly thereafter.

The Mexican territories, which were overwhelmingly anti-slavery, petitioned Washington with statehood, with the condition of the abolition of slavery. The deal was struck, and the free states of Guerrero, Morelos, and Oaxaca were admitted in Southern Mexico. (Hidalgo was co-opted by the CSA, and pro-slavery politicians put in power.)

By 1862, the CSA was completely hamstrung, and cut in half. Facing fierce resistance from both north and south, the new born nation was crumbling fast.

The Last Stand of the
Golden Circle
1862-63

By 1863, the CSA, facing an increasingly untenable situation back home in Dixie, rebranded itself as the Golden Circle, aiming to establish a slave empire encompassing the Caribbean and Central America.

Fortunately, their ambitions in Mexico were short-lived, and under the weight of brutal warfare and the logistical nightmare of fighting on multiple fronts. The Union, with the help of the new Mexican states, managed to turn the tide, leading to significant victories that further weakened the CSA’s position in both the North and the South.
The war had ended before the year was out.

Rebuilding the
American-Mexican Union
1863-67

This period was one of rebuilding and reintegration. Much like in the American South, the former Confederate and Golden Circle territories in Mexico were placed under martial law. Reconstruction focused on rebuilding infrastructure, restoring order, and fostering economic integration.

New states such as Nickajack, Winn, and Jones were created in recognition of the counties—like Fannin, Dade, Winston, Scott, and of course the eponymous Winn and Jones — that had rebelled against their own rebelling Confederate states. These counties had long resisted secession and played a vital role in undermining Confederate efforts during the war.

However, the process of full social and political integration across all these territories and states would take decades. The wounds of both wars were fresh, and the path to unity was fraught with challenges.

A Continental Superpower
1867-73

By the early 1870s, the dust had finally settled from the Civil War. After 25 years of struggle and conflict, the U.S. had completed its annexation of Mexico and most of Central America, with new Mexican territories fully integrated into the Union. The period of martial law had ended, and federal territories like Durango and Jefferson were on the path to statehood.

Economic integration was a key focus, with the revitalization of Mexico’s ports leading to increased trade and prosperity. The U.S. had emerged as a continental power, stretching from the Arctic Circle to the Yucatan Peninsula. However, the cultural and political challenges of integrating such a vast and diverse territory were ongoing, and the legacy of annexation left lasting scars on both nations.