I wonder if there were any direct flights from Chicago to Europe in the mid-fifties? O’Hare didn’t open till 1955 it seems and was underused initially. I knew that Pan Am had no domestic coverage until they started very limited through-plane services with Delta and Northwest around 1970. And although Pan Am listed Jerusalem(Jordan) in 1953 I see the flight number was ME… so Middle East Airlines?, and anyway I imagine not an option from Israel. KLM served Tel-Aviv -Yafo via Rome so they or possibly other European airlines could have connected to New York.