That’s right. I believe he was not allowed in this country for a long time because of his associations. That was changed when he was well up in age, too old to present a threat.
He was living and working in the United States for somewhere around 30 years without becoming a citizen.
In the early 1950s, he took a cruise to Europe with intentions of returning to the states from his trip.
While on board the ship he received a message that the government wanted to question him upon his return about his communist ties and such. He would be allowed to re-enter the country and stay if he agreed to submit himself to this interrogation. Otherwise, he wouldn’t be allowed to come back to the United States. Chaplin chose to not come back and eventually settled in switzerland.