Below are images of each of the declarations of war passed by Congress, available from the National Archives through the Senate website. Only three of the declarations did not involve countries associated with World War I or World War II.
Declaration of war with Great Britain (passed June 17, 1812)
Declaration of war with Mexico (passed May 12, 1846)
Declaration of war with Spain (passed April 25, 1898)
Declaration of war with Germany (passed April 6, 1917)
Declaration of war with Austria-Hungary (passed Dec. 7, 1917)
Declaration of war with Japan (passed Dec. 8, 1941)
Declaration of war with Germany (passed Dec. 11, 1941)
Declaration of war with Italy (passed Dec. 11, 1941)
Declaration of war with Bulgaria (passed June 4, 1942)
Declaration of war with Hungary (passed June 4, 1942)
Declaration of war with Rumania (now Romania; passed June 4, 1942)