(Part I) The 70s jumped from the era of Mad Men to the era of Mad Mustaches. Wide-lapel suits became the norm. The Flyers reigned supreme among Philly sports teams. But the Bicentennial was the big focus in Philadelphia. If you didn't live through it, the ubiquity of the Bicentennial is hard to explain. We enjoyed rummaging through the tacky 70s so much, that we're breaking this gallery into two parts. Check back soon for Part II.