For four seasons, Mad Men has reminded us of important differences between the sixties and today, involving politics, gender, race, class, sexuality, the media, advertising, and the working world. But the racism, homophobia, and casual sexism has not been nearly as shocking as the reminder that white Americans once wore pajamas. And nighties. Like, all the time. Seriously. Even when they were shooting pigeons. From Don’s look-alike striped pj’s to Betty’s elaborate nightgowns and Trudy’s spectacular pregnancy tutu, sleepwear has been just as important a part of the Mad Men style as Don’s steel-gray suits and Joan’s secretary pen. Don’t believe us? Vulture has done the hard historical research and returned with photographic proof.