The Mid-European Union was a post-World War I political association established in the United States of America on 16 September 1918 "to negotiate territorial disputes between the emerging nations" of Central Europe "and to work towards some form of federal union or economic alliance."
On 26 October 1918, Thomas Masaryk proclaimed the association's Declaration of Common Aims for the independence for the Czechoslovaks, Poles, Yugoslavs, Ukrainians, Uhro-Rusyns, Lithuanians, Romanians, Italian-Irredentists, Unredeemed Greeks, Albanians, Zionists, and Armenians. This occurred at a meeting in Philadelphia, Pennsylvania, at Independence Hall.