Secret of the Underground Passage - 1911 was released on:
USA: 14 October 1911
Secret Sound Underground - 2013 was released on: USA: February 2013
Ghost Mine - 2013 Secret Passage 1-5 was released on: USA: 2013
Modern Marvels - 1994 Secret Underground 17-7 was released on: USA: 10 December 2010
Northwest Passage - 1958 The Secret of the Cliff 1-17 was released on: USA: 9 January 1959
The Adventures of Ozzie and Harriet - 1952 Secret Passage 14-7 was released on: USA: 27 October 1965
The Baby-Sitters Club - 1990 Claudia and the Secret Passage 1-8 was released on: USA: 19 February 1990
The Secret Lives of Sock Monkeys - 2004 was released on: USA: 13 November 2004 (San Francisco Underground Short Film Festival)
Underground - 1972 was released on: USA: 1972
The Underground - 2006 was released on: USA: 14 September 2006
XM Underground - 2008 was released on: USA: 2008
Welcome to the Underground - 2011 was released on: USA: 2011
The Underground Railroad - 2014 was released on: USA: 2014