Only a river separates Philly’s Old City from the high property taxes and general New Jerseyness of New Jersey. The closeness is obvious when you use the pedestrian lanes of the Ben Franklin Bridge. (Bridge Walkways) If you make it all the way to the Jersey side, the path narrows and leads to a stairway.
Is this the only pedestrian bridge connecting two states? I don’t know, but since facts don’t matter anymore, I’ll say it is. And in hot weather you can get a suns out guns out photo with the Philly skyline.