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11 Times Congress Has Declared War On Another Country, And Why

"Congress shall have power to ... declare War" But Congress hasn't actually declared war since World War II.

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Editors' Note

This post has been corrected to remove phrasing that was copied from Wikipedia, Prof. Boerner's Explanations, and

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1. After the American revolution there were many unresolved conflicts with Great Britain.

Trade restrictions, American merchant sailors being pressed into service in the Royal Navy, and British support of American Indian tribes.


2. In 1821 Mexico was trying to maintain control over a vast Spanish territory after their recent independence from Spain. When Texas declared independence, a border war broke out between Mexico and the United States.

The border dispute led to a bloody conflict where 16 American solders were killed. President Polk went to Congress and demanded a declaration of war saying "Mexico has passed the boundary of the United States, has invaded our territory and shed American blood upon American soil."


3. Revolts against Spanish rule had been occurring for some years in Cuba; In 1898 President McKinley sent the USS Maine to Havana after riots threatened American citizens.

On February 15, 1898, a massive explosion sank the ship and killed 288 American sailors. This swayed popular opinion for American intervention in the war, even though the cause of the explosion has never truly been determined.

The 10-week conflict ended in decisive American victories against outnumbered Spanish forces.

The 1898 Treaty of Paris allowed temporary American control of Cuba, ceded indefinite colonial authority over Puerto Rico, Guam, Philippine islands and precipitated the collapse of the Spanish Empire.


4. In 1914, World War I broke out between Germany and Austria-Hungary and United Kingdom, France and the Russian Empire. America did not intervene in this war for the first three years.

But in 1917, Americans were made aware of a German plan to finance a Mexican war to help recover the territories of Texas, New Mexico, and Arizona.

The secret telegram, deciphered by the British and presented to the American President soon after led to cries for American involvement.


After the collapse of German lines in 1918 an armistice was signed. The 1919 Versailles Treaty formally ended the declaration of war between the Allies and Germany.

Treaties with Austria, Hungary, Bulgaria, and the Ottoman Empire were subsequently signed.


The American Congress has not formally declared war on any nation since. / Via Doug Dunbar/KTVT/KTXA

Congress has voted 23 times to authorize limited military engagements including Vietnam, Iraq and Afghanistan. Many of these votes come after American forces have already been engaged by the executive branch.

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