G.A.R. Memorial Hall, also known as the Algona Schoolhouse, is a historic building located in Algona, Iowa, because of declining numbers, the local G.A.R. Post gave the building to Hagg Post No. 90 of which U.S. wartime veterans organization formed in Paris, on February 16, 1919, by three officers of the American Expeditionary Forces (AEF) ?