What countries were involved in the Allied campaign during World War 2 and in what month and year did each join the effort?

Poland: 1 September 1939

Britain, France: 3 September 1939

Canada: 9 September 1939

Norway, Denmark: 9 April 1940 (upon invasion)

Belgium, Luxembourg, Netherlands: 10 May 1940 (upon invasion)

Czechoslovakian government-in-exile: 21 July 1940

Greece: 28 October 1940 (upon invasion)

Yugoslavia: 27 March 1941 (left Axis after a coup)

Soviet Union: 22 June 1941 (upon invasion by Nazi Germany)

United States: 7 December 1941 (Pearl Harbor attack by Japanese)

China: 9 December 1941 (parts of China already occupied by Japan since early 1930s)

Mexico: 1 June 1942

Brazil: 22 August 1942

Iran: 9 September 1943

Ecuador: 2 February 1945

Paraguay: 8 February 1945

Peru: 12 February 1945

Uruguay: 14 February 1945

Turkey: 25 February 1945

Argentina: 28 March 1945