Northeastern Dialects
Most of the major cities of the Northeast Megalopolis have distinctive accents that cover smaller regions than the broad "North" and "Midland" categories of the Midwest, reflecting the greater dialect diversity of the Northeast. These dialects are not all closely related to each other, but subsets of them share several unusual features, such as non-rhoticity or a split of /æ/ into two separate phonemes.
One feature shared by all of them is resistance to the Mary–marry–merry merger. Similarly, these dialects retain a distinction between historical short o and long o before intervocalic /r/, so that, for example, orange, Florida, and horrible have a different stressed vowel than story and chorus.
Read more about this topic: North American English Regional Phonology