"I graduated from New Haven in 1915"

Connecticut Hall, Yale University Old Campus
Public DomainConnecticut Hall, Yale University Old Campus - Credit: Ragesoss, Wikimedia Commons
Although there is now a University of New Haven (founded in 1920), it is likely that the reference here is to Yale University which is located in New Haven, Connecticut.

Yale is one of the most prestigious universities in the United States and has many distinguished alumni.

Originally a men-only college, it began admitting women in 1969.