This present-day map of Essex County, Massachusetts, (source: mass-doc.com) shows the detail of towns where I find my Lowell ancestors. The names of current cities are capitalized; towns are not.
The dates of settlement or incorporation are in parentheses. Newbury (1635), Newburyport (1764, from Newbury), Salisbury (1639), Amesbury (1666, from Salisbury). (The Atlantic Ocean is to the east and New Hampshire is to the north.)
If this looks familiar, it is because my Greeley ancestors settled in Salisbury and later moved inland to Haverhill (1640).