If you haven’t heard of the Dictionary of American Regional English (DARE), let me recommend it to you highly.
Joan Hall, DARE’s executive editor, will be my guest on In a Manner of Speaking in August. She has just told me that Harvard University Press is offering a 25% discount on the digital version of DARE until the end of June for all organizations and institutions. If your library has not purchased it, now is the time to urge that it do so. (There is a 30-day free trial.) Visit Harvard.edu for details.
And an individual subscription to digital DARE is available for $49 per year. See Harvard.edu.