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Official Declarations of War by Congress


The Constitution grants Congress the sole power to declare war. Congress has declared war on 11 occasions, including its first declaration of war with Great Britain in 1812. Congress approved its last formal declaration of war during World War II. Since that time it has agreed to resolutions authorizing the use of military force and continues to shape U.S. military policy through appropriations and oversight.


Declaration of War with Great Britain, 1812
War of 1812: Senate Amendments

On June 17, 1812, the Senate approved a resolution declaring war with Great Britain by a vote of 19-13. The House approved the measure that day, and President James Madison signed the legislation the next day, June 18, 1812, marking the first time the United States of America declared war on another nation.


Declaration of War with Mexico, 1846
H.R. 145 Declaration of War with Mexico, 1846

On May 12, 1846, Congress approved a resolution declaring war with Mexico. The Senate approved the resolution by a vote of 40-2.


Declaration of War with Spain, 1898
H.R. 10086 Declaration of War with Spain, 1898

On April 25, 1898, Congress approved a resolution declaring war with Spain by unanimous consent.


Declaration of War with Germany, 1917
S.J.Res. 1: Declaration of War With Germany, WWI

On April 6, 1917, Congress approved a resolution declaring war with Germany. The Senate approved the resolution by a vote of 82-6 on April 4, 1917.


Declaration of War with Austria-Hungary, 1917
H.J.Res.169: Declaration of War with Austria-Hungary, WWI

On December 7, 1917, Congress approved a resolution declaring war with Austria-Hungary. The Senate unanimously approved the resolution, 74-0.


Declaration of War with Japan, 1941
S.J.Res. 116: Declaration of War with Japan, WWII

On December 8, 1941, Congress approved a resolution declaring war with Japan. The Senate unanimously approved the resolution, 82-0.


Declaration of War with Germany, 1941
S.J.Res. 119: Declaration of War with Germany, WWII

On December 11, 1941, Congress approved a resolution declaring war with Germany. The Senate unanimously approved the resolution, 88-0.


Declaration of War with Italy, 1941
S.J.Res. 120: Declaration of War with Italy, WWII

On December 11, 1941, Congress approved a resolution declaring war with Italy. The Senate unanimously approved the resolution, 90-0.


Declaration of War with Bulgaria, 1942
H.R.Res. 319 Declaration of War with Bulgaria, WWII

On June 4, 1942, Congress approved a resolution declaring war with Bulgaria. The Senate unanimously approved the resolution, 73-0.


Declaration of War with Hungary, 1942
H.J.Res.320 Declaration of War with Hungary, WWII

On June 4, 1942, the Senate approved a resolution declaring war with Hungary. The Senate unanimously approved the resolution, 73-0.


Declaration of War with Rumania, 1942
H.J.Res. 321 Declaration of War with Rumania, WWII

On June 4, 1942, the Senate approved a resolution declaring war with Rumania. The Senate unanimously approved the resolution, 73-0.