First use of the iconic block-lettered X-Men logo as created by Jim Steranko.
in Los Hombres X (Editora de Periódicos La Prensa S.C.L., 1966 series) #48 (Diciembre 31 de 1969)
in The Official Marvel Index to the X-Men (Marvel, 1987 series) #3 (September 1987)
in Marvel Special (Marvel Italia, 1994 series) #16 (Marzo 1999)
in Marvel Visionaries: Jim Steranko (Marvel, 2002 series) #[nn] ([September] 2002)
in Marvel Masterworks: The X-Men (Marvel, 2003 series) #5 ([August] 2005)
in The X-Men Omnibus (Marvel, 2009 series) #2 ([April] 2011)Possible Steranko color credit by Nick Caputo. Steranko colors credit is corroborated by The Marvel Comics Index (Olshevsky 1981) and The Official Marvel Index to the X-Men (Olshevsky 1987).
in Los Hombres X (Editora de Periódicos La Prensa S.C.L., 1966 series) #48 (Diciembre 31 de 1969)
in Marvel Special (Marvel Italia, 1994 series) #16 (Marzo 1999)
in Marvel Visionaries: Jim Steranko (Marvel, 2002 series) #[nn] ([September] 2002)
in Marvel Masterworks: The X-Men (Marvel, 2003 series) #5 ([August] 2005)
in The X-Men Omnibus (Marvel, 2009 series) #2 ([April] 2011)
in Los Hombres X (Editora de Periódicos La Prensa S.C.L., 1966 series) #48 (Diciembre 31 de 1969)
in Amazing Adventures (Marvel, 1970 series) #17 (March 1973) [pages 2-5]
in X-Men: Mutations (Marvel, 1996 series) #[nn] (1996) [pages 6-9]
in Marvel Special (Marvel Italia, 1994 series) #12 (Novembre 1997) [abridged]
in Marvel Masterworks: The X-Men (Marvel, 2003 series) #5 ([August] 2005)
in The X-Men Omnibus (Marvel, 2009 series) #2 ([April] 2011)
in Essential Classic X-Men (Marvel, 2006 series) #2 (2006) [black & white]The Origins of the Uncanny X-Men! part 13, origin of the Beast part 2, page 1 of this story is not reprinted in the Amazing Adventures #17 and X-Men: Mutations #nn reprints.
in The X-Men Omnibus (Marvel, 2009 series) #2 ([April] 2011)