The Wilson administration, following the American declaration of war in April 1917, permitted the Entente powers (as well as the provisional governments of Poland and Czechoslovakia) to recruit volunteers for military service from among their nationals living in the United States. British conscription adopted in 1916 did not/not extend to America and the Wilson administration made no attempt to enforce British conscription on British subjects resident in the US. Foreign nationals of belligerent powers, permanent residents who had not yet become American citizens, were conscripted as were some nationals (American permanent residents) of neutral states such as the Netherlands and Norway. Indeed, some 20 to 25% of the AEF was made up on foreign-born Americans. Canada adopted conscription in 1917. Could you ancestor have served in Canadian forces? In those days there was no concept of Canadian (or Australian, New Zealand, South African) citizenship as distinct from British citizenship. Therefore, British-born young men in Canada would have been subject to conscription there as residents of a self-governing dominion of the British Empire.. LGS