The United States has officially declared war 11 times in five separate military conflicts. According to the Constitution (Article I, Section 8), Congress has the exclusive power to declare war. The last time America declared war was during World War II. The Korean War, the Vietnam War, and the protracted campaigns in Afghanistan and Iraq were never marked by congressional declarations of war.
1. War of 1812
Known as the “Second War of Independence,” the War of 1812 was America’s first military test as a sovereign nation. President James Madison, angered by Britain’s refusal to respect American neutrality in the ongoing conflict between Britain and France, asked Congress to declare war on his former colonial overlord.
The vote in Congress was not unanimous, with Federalists objecting to the aggressiveness of the newly elected “war hawk” legislators. But in the end, the House voted 79-49 and the Senate 19-13 to wage war against what remained the greatest military power on Earth.
Madison signed the declaration on June 18, 1812.”[W]ar . . . is declared to exist between Great Britain and its dependencies and the United States of America and its territories,” the decree read. “[A]nd…the President of the United States is hereby authorized to use the entire land and naval force of the United States to implement the same.
WATCH: First Invasion of the War of 1812 on HISTORY Vault
2. Mexican-American War
The 1846 war with Mexico began as a land dispute. In 1836, Texas gained independence from Mexico to become the Republic of Texas, but Mexico never relinquished its claim to this land. So when the United States annexed Texas in 1845, tensions escalated between the northern and southern neighbors. When President James Polk sent American troops to patrol the Rio Grande border, the Mexican army attacked, giving Polk the justification he needed to ask Congress to declare war.
Congress was even more divided over going to war with Mexico than the War of 1812. Northern Whigs saw it as unwarranted land grabbing by Southern Democrats who sought to add more slave territories to the states. -United.
Ultimately, the Whigs gave in, fearing they would suffer the same political fate as the Federalists, whose opposition to the War of 1812 led to their downfall. The Senate adopted the declaration on May 12, 1846, which began: “Whereas by the act of the Republic of Mexico, a state of war exists between this government and the United States.
3. Spanish-American War
The short-lived war between the United States and Spain began as a Cuban war for independence. American newspapers closely followed the fate of Cuban revolutionaries as they fought with Spain from 1895 to 1898, publishing sensational stories that were criticized as “yellow journalism”.
America’s involvement in the neighboring conflict was sealed by the mysterious sinking of the American warship Maine in Havana harbor on February 15, 1898.
Congress passed a resolution in April recognizing Cuba’s independence and ordering Spain to back down, but Spain refused. President William McKinley therefore responded with a US naval blockade of Cuba and called in 125,000 volunteers to enforce it. Spain immediately declared war, and the U.S. Congress followed suit on April 25, 1898.
The declaration was adopted unanimously by a voice vote in both houses. The war ended on December 10 with the Treaty of Paris, in which Spain not only granted Cuba its independence, but ceded the territories of Guam and Puerto Rico to the United States. Spain also agreed to sell the Philippines to the United States for $20 million.
4. World War I – Germany
President Woodrow Wilson was not eager to enter World War I. Even after the 1915 sinking of the British liners the Lusitania and the Arab by German U-boats, in which 131 American citizens were killed, Wilson held back. Instead of declaring war, he made the Germans promise to stop attacks on Allied civilian ships.
By 1917, however, the Germans had recalculated and decided to risk US involvement in World War I by re-establishing their attacks on civilian shipping in the North Atlantic, thinking they could win the war before the Americans cannot enter.
On April 2, 1917, Wilson petitioned Congress to declare war on Germany, citing its renewed submarine attacks and attempts to recruit Mexico as an enemy of the United States. The statement passed by wide margins in both the House (373-50) and the Senate (82-6). American forces suffered over 320,000 deaths during World War I, including over 116,000 dead.
WATCH: World War I documentaries on HISTORY Vault
5. World War I – Austria-Hungary
On July 28, 1814, Austria-Hungary declared war on Serbia in retaliation for the assassination of Archduke Franz Ferdinand of Austria and his wife by Serbian nationalists. Germany immediately allied itself with its Austria-Hungary, setting off a political domino effect that brought all major European powers to war within days.
On December 10, eight months after the United States declared war on Germany, Congress passed a separate declaration of war against Austria-Hungary, citing the empire’s complicity in sub-military attacks. German sailors against American ships.
READ MORE: 8 events that led to the outbreak of World War I
6. World War II – Japan
Early in the afternoon of December 7, 1941, Japan launched a devastating surprise attack on the American naval installations at Pearl Harbor, Hawaii. After less than two hours of aerial bombardment, most of the Pacific Fleet was sunk and 3,500 American servicemen were killed or wounded.
That day, President Franklin D. Roosevelt wrote his iconic speech to Congress calling for a declaration of war against Japan for the “unprovoked and despicable attack.” And on December 8, Roosevelt addressed Congress and the nation, calling December 7, 1941 “a date that will live in infamy.” The congressional response was swift, with a near unanimous roll-call vote in the House (the only dissenter was pacifist Jeannette Rankin of Montana) and a unanimous declaration of war in the Senate.
WATCH: Pearl Harbor: The Last Word on HISTORY Vault
7. – 8. WWII – Germany and Italy
Just four days after the Japanese attack on Pearl Harbor, while Americans were still reeling from grief and anger, Nazi leader Adolf Hitler of Germany delivered another surprise by declaring war on the United States. Fascist Italy, bound by an Axis pact signed in 1940, also declared war on America.
On December 11, 1941, Roosevelt sent a message to Congress again asking for a declaration of war. “The forces that are trying to enslave the whole world are now moving towards this hemisphere,” Roosevelt wrote. “The swift and united effort of all the peoples of the world who are determined to remain free will ensure [sic] a worldwide victory of the forces of justice and righteousness over the forces of savagery and barbarism”.
This time, there were absolutely no dissenters. In the House, Rankin chose to vote “present” instead of “no”, bringing the vote to 393 to 0.
9.-11. World War II – Bulgaria, Hungary and Romania
On June 3, 1942, Roosevelt signed three final declarations of war against the remaining Axis powers. Bulgaria, Hungary and Romania each had their own reasons for allying with Germany in 1940. Bulgaria had territorial disputes with Yugoslavia and Greece and thought Germany could provide muscle. Hungary was afraid of being swallowed up by the Soviet Union. And Romania was ruled by fascists and anti-Semites who sided with the Nazis.
In his letter to Congress, Roosevelt wrote, “I realize that all three governments have taken this step [declaring war on the United States] not on their own initiative or in response to the wishes of their own peoples, but as instruments of Hitler.
These three declarations of war during World War II were the last ever adopted by the United States Congress. All the wars that followed – the Korean War, the Vietnam War, the wars in Afghanistan and Iraq – were either started by an “Authorization for the Use of Military Force” (AUMF) from Congress or , in Korea’s case, not authorized by Congress at all.