I am in Maryland which is smack in the middle of the Northeast and the American South. It's a mixed bag.
So, some words you think might rhyme do not.
Sad and had do not rhyme with mad and bad. The two former words might sound like you'd expect the short a sound to be.
However, mad and bad have almost two vowel sounds, more like mayud and bayud, ( see also dayumn! when you're really angry )
And, the Baltimore long o sound is almost a long oo sound, as in food. And, everybody calls everybody hon, short for honey, but the pronunciation is weird. Think the short oo sound as in hook and then add in on the end. Something like hooin. This is a dying accent and only some of the town spoke it and it was mainly a working class accent.
You might hear something like this when asking about the Orioles baseball team :
"Didja hear bout them Oo's?"
"No, hooin! Jew?" (No, hon. Did you?)
Also, "Jeet yet?" means Did you eat yet?
Baltimoreans also warsh their cloothes in the zink with wooder sometimes when the warshing machine is dee-oin.
(Wash their clothes in the sink with water when the washing machine is down.)
Down in another weird one pronounced with two vowel sounds like dee and then oin, but blended together quickly.
And in the summer, they'll go "Downy oocean, hoo-in." for vacation. (Down to the ocean, hon.)