Yes much (if not most) of the US still has copper lines if they even have a landline. I don't expect that to last much longer with more areas getting fiber lines for cable/internet. My last house had phone jacks with copper to the telco but my current house has no phone line. I think they will die out with the boomers - everyone else just uses mobile phones now unless they get phone service through their cable company or (a small minority) VOIP providers.