The war in Europe had an immediate and direct impact on North America. The United States and Canada acted on their strong cultural, economic and political ties to Britain by contributing men, money and material to the Allied side in the First World War. The strong US-British trading and financial wartime relationship evolved naturally from pre-existing bonds. In 1919, Mexican President Venustiano Carranza vocally disputed Woodrow Wilson's claim that the Monroe Doctrine benefited nations seeking to determine their own futures. The absence of a national monument to the war in Washington, DC, stands in notable contrast to the dominating presence of the Peace Tower and the National War Memorial in Ottawa. The 1932 Ottawa Conference, for instance, established a five-year privileged trading relationship among Britain and its Dominions at the height of the Great Depression.