 Complete the following phrase:  From 1943 to 1946, Keller served as an officer of the U.S. 5th Army in the Monuments, Fine Arts, and Archives program. Captain Keller was primarily responsible for the identification and transportation of artworks in Tuscany, Italy, the center of the Italian Renaissance and a major site of Nazi looting. He worked in Pisa and Florence, where Nazi troops had bombed churches, destroyed or dislocated public art, and seized paintings from museums including the Uffizi. As they were discovered during the 