My grandparents lived on Keystone St in Philadelphia and the Northeast Corridor ran right behind their house. I can remember as a kid in the late 60's and 70's freights being pulled by GG1's and E44's all the time.
Conrail still exists as a terminal railroad operation in northern NJ, southern NJ & Philadelphia as well as around Detroit, MI. There was also a good article in the October 2012 issue of Trains Magazine on current Conrail operations.