Kelsey's first major expedition following World War I had several goals. He visited and photographed Caesar's battlefields and other archaeological sites and monuments in the Mediterranean region. Wherever he could, he bought artifacts, manuscripts, and papyri for the University. At the Monastery of Saint John on the Greek island of Patmos, he orchestrated a campaign to photograph the library of rare manuscripts. In Asia Minor he consulted with missionaries who worked among the Armenian population in the region of Cilicia, where relief efforts were under way. Later, Kelsey undertook three significant archaeological projects: one at the imperial Roman colony of Pisidian Antioch in Asia Minor, a second at the Graeco-Roman farming town of Karanis in Egypt, and a third at the Sanctuary of the Phoenician deities Baal Hamon and Tanit at Carthage in Tunisia. In Pompeii, he contracted with artist Maria Barosso to paint watercolor replicas of the murals at the Villa of the Mysteries.