Happy Thanksgiving to All, My grandfather's gravestone is engraved with the following: GREEN DEZARN INDIANA CHAUFFEUR 645 AERO SQ WORLD WAR I SEPT 30 1895 JULY 28 1960 My searches on the Internet have thus far not revealed any references to what I'm assuming is the "645th Aero Squadron." Could someone provide information regarding this World War I unit? Thank you to all who may respond. Donald DeZarn