"Hello? CHestnut 7180. I'd like to speak to Thomas Jefferson please."After visiting the Jefferson Memorial, Billie Dawn (Judy Holliday) dials.
Someone on the set didn't know how to spell DEcatur, which was, according to the Telephone EXchange Name Project, a Washington, D.C. exchange name. But there's no sign that CHestnut was in use in D.C. I like it that both the written number and the spoken number are missing a digit.