At a hotel in the White Mountains, a man arrives to check in for his honeymoon stay. When he identifies as Jewish and asks if there is a policy against Jewish guests, he is told there is suddenly no vacancy, recommended to go to another hotel and ushered out the door. This is a scene from “Gentleman’s Agreement,” a 1947 Gregory Peck feature film about antisemitism that marks its 75th anniversary this year. It’s also one of 10 films spotlighted by experts as among the most significant to address antisemitism.