The flags of Mexico and California State on adjacent poles hang high against a clear blue sky.

The Lasting Impact of the Treaty of Guadalupe Hidalgo

February 2, 2023, is the 175th anniversary of the signing of the Treaty of Guadalupe Hidalgo, which marked the end of the U.S. invasion of Mexico. Though the Mexican-American War is barely remembered in the United States, it dramatically reshaped both nations, and its effects on Mexico-U.S. relations reverberate to this day. Were it not for this brutal invasion, the United States as we know it today would not exist (History). 

Why did the U.S. start the Mexican-American War? 

To expand slavery. Since Mexico abolished slavery, white American slave owners in Mexico seceded and formed the sovereign Republic of Texas in 1836. Texas joined the United States as a slave state in 1845. When the Mexican military moved to enforce its northern border with Texas, Congress declared war on Mexico (History). 


• Support Movimiento Cosecha, PCUN, Juntos, and grassroots Latine organizing in your community.

• Support Teaching for Change and join the Banned Books Book Club to promote accurate education about U.S. history.

• Support the Mexico Solidarity Network, Farm Labor Organizing Committee, and other groups organizing and building solidarity across the border. 

What were the results? 

The U.S. military eventually occupied Mexico City and forced the Mexican government to cede the northern half of Mexico to the United States: the current states of Arizona, California, Colorado, Nevada, New Mexico, Texas, Utah, and Wyoming (Encyclopedia).

Why didn’t the U.S. take over all of Mexico? 

Because of racism. The U.S. government didn’t want non-white Mexicans as citizens. Here’s Senator John C. Calhoun, one of the most prominent U.S. politicians of the 19th century: 

“[We] have never dreamt of incorporating into our Union any but the Caucasian race the free white race. To incorporate Mexico, would be the very first instance of the kind of incorporating an Indian race; for more than half of the Mexicans are Indians, and the other is composed chiefly of mixed tribes…

“Ours, sir, is the Government of a white race. The great misfortunes of Spanish America are to be traced to the fatal error of placing these colored races on an equality with the white race.” (CUNY)

What are the effects of the U.S. invasion today? 

The residents of the land seized by the United States were “lynched, harassed, relegated to second class status, and treated as foreigners in their ancestral land.” The new white ruling class “wanted to send a clear message to the newly conquered people that there was a new racial hierarchy which would reign over the land” (CounterPunch). The murderous border enforcement and anti-Latine domestic policies of the contemporary United States can be traced back to the theft of northern Mexico with the Treaty of Guadalupe Hidalgo. 

When the U.S. stole half of a neighboring country, it escalated tensions with Mexico and the rest of the Americas. The U.S. would later intervene militarily in Argentina, Bolivia, Chile, Colombia, Cuba, the Dominican Republic, El Salvador, Grenada, Guatemala, HaitiHonduras, Nicaragua, Panama, and Puerto Rico: overthrowing governments, training death squads, and protecting corporate interests (Evergreen State College).

What does this mean for us?

White supremacy is almost always the deciding factor in U.S. history. The U.S. started the war to expand slavery and stopped short of taking over all of Mexico to preserve the whiteness of the U.S. electorate. Leaders of the time said as much on the Senate floor and in national newspapers. That’s why teaching U.S. history without “critical race theory” leads to absurd distortions of the historical record. 

U.S. brutality towards Latin America and Latine people wasn’t a problem unique to the Trump years. It literally shaped the United States itself. And even now, the Biden administration is unashamedly continuing Trump’s draconian immigration policies, giving lip service to diversity while sending immigration agents to terrorize immigrant communities. Those policies and the people who enforce them, Democrats or Republicans, are equally repugnant.

We can transform Mexico-U.S. relations by widening our perspective on social justice to an internationalist frame. Though there are enormous differences in power, wealth, and privilege between people on either side of the border, we can begin to dismantle these inequities by coming together in solidarity and ensuring that our vision of justice isn’t limited by the borders imposed by a white supremacist government. 


• The U.S. invasion of Mexico ended with the signing of the Treaty of Guadalupe Hidalgo.

• Mexico was forced to cede half of its territory, the current states of Arizona, California, Colorado, Nevada, New Mexico, Texas, Utah, and Wyoming.

• The invasion has direct effects on present-day domestic and international injustices.

1920 1200 Andrew Lee

Andrew Lee

Andrew Lee is a writer and organizer plotting a better world in Philadelphia. His work has previously appeared in Notes From Below, Perspectives on Anarchist Theory, Plan A Magazine, ROAR Magazine, and Teen Vogue.

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