Conversation so far:
what did Vladimir Nabokov do for the us?
Vladimir Nabokov joined the staff of Wellesley College in 1941 as resident lecturer in comparative literature. He was also the founder of Wellesley's Russian Department.
Are there any other interesting aspects about Vladimir Nabokov?
Vladimir Nabokov became an American citizen in 1945.

Question: what was his biggest achievment?
Self-contained rewrite: what was Vladimir Nabokov's biggest achievment?