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Proclamation Declaring a State of War with Mexico

James K. Polk · 1846

Polk's printed proclamation announcing that a state of war existed between the United States and Mexico, signed by him and Secretary of State James Buchanan.

Polk signed this proclamation as president, formally declaring war with Mexico.

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Scan of a printed proclamation headed 'By the President of the United States of America. A Proclamation.' beneath an eagle seal. Signed James K. Polk, with James Buchanan as Secretary of State. Paper is aged and stained at the edges.
James K. Polk, Proclamation of a State of War with Mexico, 1846.

About this source

What it is

This is a printed proclamation issued by President James K. Polk, announcing that Congress had declared a state of war existed between the United States and Mexico. It is signed by Polk, with James Buchanan as Secretary of State.

Why it matters

The proclamation shows the formal executive step that followed Congress's declaration of war in 1846. It documents how Polk, working with his cabinet including Buchanan, turned a congressional decision into official government action, starting the Mexican-American War that reshaped the United States' territory.

Look closer

  • What words does the document use to explain who started the war, and why might that matter?
  • Why would a president need to issue a public proclamation rather than just letting Congress's declaration stand alone?
  • What does the eagle seal and formal language tell you about the document's purpose?

This document is part of the curated material that grounds the AI version of James K. Polk on Humy.ai — when students ask about related events, the AI can quote it and cite it.

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