After World War I, the New York City subway added extensions that contributed to the increased population of Jews in the Bronx. In addition to Jews, many French, German, and Polish immigrants moved into the Bronx. However, in the 1930s residents started moving out due to high crime rates and gangs. The first population to leave was the Irish after the 1930s, then the Germans followed in the 1940s, the Italians in the 1950s, and finally the Jews in the 1960s. From 1923-1930, the Jewish population had grown from 382,000 to its peak population of 585,000. Then, gradually the Jewish population fell to 538,000 in 1940, to 519,000 in 1950, and 493,000 in 1960.
In the 1940s, the Royal Photoplays Theatre, now renamed the Radio Theatre, started screening Soviet films from a controversial film company called Artkino Pictures. This followed a trend of Communist films being shown at theaters during the period. The President of Artkino Pictures was Nicola Napoli, an Italian who also edited a Communist publication and became an employee of Amkino Corp (not to be confused with Artkino Pictires), a US distributor of Soviet films. For his Soviet affiliations, Napoli was registered with the Department of State as an agent of the Soviet Government. Radio Theatre closed in 1947 as its main customer base began to leave the area and as the post-World War II Red Scare took hold of the city and nation.