Conversation so far:
What did Vladimir Nabokov do in the United States?
The Nabokovs settled in Manhattan and Vladimir began volunteer work as an entomologist at the American Museum of Natural History.
Did Vladimir Nabokov do other work after that?
Nabokov worked at  Wellesley College in 1941 as resident lecturer in comparative literature. The position, specifically for him, provided income and free time to write creatively and pursue his lepidoptery.
Did Vladimir Nabokov like his job as resident lecturer at Wellesley College?
Did Vladimir Nabokov stay at Wellesley College?
The Nabokovs resided in Wellesley during the 1941–42 academic year. In September 1942 they moved to Cambridge. Nabokov returned to Wellesley for the 1944–45 academic year.

Question: What happened after 1948?
Self-contained rewrite: What happened after 1948 with Vladimir Nabokov?