During prohibition, speakeasies used a variety of methods to identify genuine customers from undercover agents. Initially, bouncers relied only on personal recognition, but as the industry grew, this individualized approach became unsustainable. Some bars used secret passwords or special knocks, but the majority printed membership cards, which customers had to present in order to gain entry. A surprising number of these cards are personalized. They were assigned to specific customers and explicitly state they are non-transferable. Others are more basic and resemble modern-day business cards. Though, even these appear to contain subtle cues to indicate the true nature of their business. Taken together, these cards provide a small, but fascinating glimpse into the illicit drinking culture that flourished in New York City from 1920 to 1933.
