Back in those days a number of people with Jewish, Italian, German, or Polish names anglicized them for professional reasons. In some cities with large Irish populations, I’ve read that Jewish or Italian boxers would change their names to an Irish name and even call themselves Irish Mike McBride or Irish Dan Malone. And of course, many people in showbiz anglicized/prettified their ethnic names i.e. Frances Gumm became Judy Garland.
The actor Archibald Leach was born in England but for some inexplicable reason decided to change his name to Cary Grant.