No player has ever worn number 70 for Chicago.
Eric Nesterenko, "old elbows"
Pete Conacher, Bronco Horvath, Nick Mickoski, Dutch Reibel, Tod Sloan, Steve Witiuk and Bobby Hull. The # 9 is now retired within the Blackhawks organization.
Mike Hudson - 1988-90 Milan Tichy - 1992-93 Nathan Dempsey - 2002-04 James Wisniewski - 2006-09 Brandon Saad - 2011-12
In 2010, wide receiver Johnny Knox wore #13 for the Chicago Bears.
You wore 'threads' in the seventies.
They wore them around their necks.
Michael Jordan wore number 23 on the Chicago Bulls.
Carlos Boozer
John Paxson
According to NHL Tags and Tails, the NHL wore Nike jerseys with the "swoosh" and NHL logo on the tail from 96-97 to 98-99.
As far as I know there is nobody currently wearing the number 68 but Jaromir Jagr, Milan Jurcina, and Zigmund Palffy wore it.