Before 1949, U.S. airlines didn’t serve alcohol in flight, writes Rust in Flying Across America: The Airline Passenger Experience. But when a few airlines eventually decided to serve alcohol, that didn’t mean it was easy to do so. Because of conflicting state liquor laws, drinks could be served only over certain states. The New York Times reported in 1950 that on a flight leaving New York for the West Coast, passengers could drink over New Jersey, but not over Pennsylvania, a no-sale state. On Northwest Airlines’ two-deck Stratocruisers, bar attendants were given a chart of state liquor sale restrictions. “The chart lists the states along the route, and for each state gives prohibited hours, prohibited days and restrictions to persons served,” the article reports. “The attendant judges from landmarks, his own watch or advice from pilots whether—and to whom—he can serve drinks.” (That includes refusing drinks to “spendthrifts” when flying over South Dakota, for some reason.) The attendant also knew that drinks couldn’t be served on Sundays, election days, certain other holidays, and specific hours in some states.