Assuming you're looking for quaint walkable towns (and not stressing over the fact that they're surrounded by miles of car-dependent suburbs and rural areas), you can find them anywhere and everywhere. Most small/medium sized towns on the east coast have a historic/old town that is like this, for example in Virginia state:

Culpeper, VA [0] (passenger railroad station right in downtown that connects to all the big cities on the east coast)

Warrenton, VA [1] (Ridiculously good downtown restaurant scene, whenever I go there there always seems to be some festival or market happening)

Staunton, VA [2] (Beautiful area surrounded by some of the largest tracts of public land in the eastern US)

Fredericksburg, VA [3] (tons of interesting history here)

Charlottesville, VA [4] (look at that pedestrian-only shopping street a block away!)

[0] https://www.google.com/maps/@38.4731207,-77.9962447,3a,75y,1...

[1] https://www.google.com/maps/@38.7131072,-77.7940715,3a,60y,2...

[2] https://www.google.com/maps/@38.1496218,-79.0715993,3a,75y,1...

[3] https://www.google.com/maps/@38.3031279,-77.460567,3a,75y,16...

[4] https://www.google.com/maps/@38.031349,-78.4795003,3a,60y,20...