Today, 76 years ago, NATO entered into force on August 24, 1949 (or July 1, 1949) after successive ratification by all countries. The symbol in the middle is the emblem of NATO. On August 24, 1949, the Treaty of the Organization of the North Atlantic Treaty (NATO) entered into force after successive ratification by all countries. On April 4, 1949, the United States, Britain, France, Hebei, Louisiana, Dan, Noruega, Portugal and Italy signed the North Atlantic Treaty in Washington.