Congress
In the United States, only a joint resolution of Congress can officially declare war.
The executive order goes around Congress' ability to declare war. Basically, the president has the ability to declare war (though not officially).
The legislative branch.
Congress ; see related link .
September 2, 1945.
The United States Congress officially declared war on Germany on April 6, 1917. President Woodrow Wilson asked for a declaration on April 2.
September 3 1939 give or take a few days
To announce officially; proclaim: to declare a state of emergency; to declare a winner.
No, of course not! Only Congress may officially declare war. The President of the United States may order military action without a formal declaration of war. The Chairman of the Joint Chiefs of Staff cannot declare war and he cannot order a military strike on another country without permission from the White House. However, once war has been declared or a military action has been ordered, the professional military officers (with the Chairman of the JCS at the top) handle the operational details.
Officially on July 4, 1776 via the Declaration of Independence which officially made the war about independence and not maintaining the status quo.
Different countries do it in different ways. In the US, only Congress can do it- but the Constitution doesn't specify exactly how, so it's always been done basically like passing a law. In countries that have a monarch, like Britain or Japan (before World War II), that monarch has the sole power to declare war, but they usually consult their advisors before doing so.
you declare war