 During World War II , the surrounding neighbourhood was devastated , but the building itself was left largely intact ( and inhabited by the homeless citizens of a bomb @-@ ravaged Frankfurt ) . In March 1945 , Allied troops occupied the area and the IG Farben Building became the American headquarters of General Dwight D. Eisenhower . Eisenhower 's office was where he received many important guests ; including General de Gaulle , Field Marshal Montgomery and Marshal Zhukov . It was there that he signed the " Proclamation No. 2 " , which determined which parts of the country would be within the American zone . Eisenhower vacated the building in December 1945 but his office was still used for special occasions : the constitution of the state of Hesse was signed there , the West German Ministerpräsident received his commission to compile the Grundgesetz ( German constitution ) and the administration of the Wirtschaftsrat der Bizone ( Economic Council of the Bizone ) was also located there . 
