Berg grew up in an immigrant Jewish family in Newark, New Jersey. He caught and fielded for five American baseball teams from the 1920s through 1939 during baseball’s Golden Age. Berg also had a secret life spying on the Japanese during his time with the All American team’s tour of Japan and later working for the U.S. Office of Strategic Services (OSS) during World War II. He played a prominent role in U.S. efforts to undermine the German atomic bomb program and is now remembered most as the catcher who was a spy. Berg is considered a hero especially to American Jews.