So let's make this another of the multi-card entries in Atlantic City Week here at PotD. Can you guess today's theme (within the theme)?
Hint, it's not about hotels or buildings, per se.
Hmm, I didn't find any postcards with railroads on them....
For these last one to help, if you haven't clicked the jump cuts, you'd have to know the name of the little plaza shown. I'll put that answer in the comments.