Hawthorne is not a minor author, but he also did not write in Boston.
He may not have written The Scarlett Letter in Boston, but he did write several short stories while living in Boston. He lived at 54 Pinckney Street and also at 8 Somerset Place. These short stories were commercially unsuccessful. He did work at one time at the Boston Custom House.
Meadowhawk, point conceded, but, from the standpoint of residence, Hawthorne is primarily associated with Salem, Concord, and Lenox.
Even casting a wider net, I'm not sure that a Massachusetts Museum of Arts and Letters would be a draw. Now if you could strike a deal with Harvard to borrow the Glass Flowers, that could bring crowds. Or better yet, find another pair of glass blowers and create your own silica arboretum.