Green’s Dictionary of Slang

(US) Indianapolis, Indiana.

1929		‘Naptown Stomp‘ [song title].
c.1930		Leroy Carr & Scrapper Blackwell [song title] Naptown Blues.
1959		in National Geographic Mag. 231: A sleepy crossroads city nicknamed ‘Nap-town’ and ‘India-no-place’.
1972		Milner & Milner Black Players 113: They was from Detroit and Chicago, Naptown [...] and New York.
1985		A. Lelchuk Miriam in Her Forties 239: ‘We don’t get that much variety in Nap Town.’ Miriam nodded, started to ask something about Indianapolis, when the phone interrupted.
1997		E. Little Another Day in Paradise 230: They got a score in Nap Town.
2006		T. Blaine Meth Monster: The Story of a Resurrected Life 11: Maybe my mother saw Billy as her ticket out of Nap Town (Indianapolis).