The town allowed liquor sales in the 1970s, but so far as I know it only applies to restaurants and clubs: they've kept liquor stores out of the town.
Needham is still listed as an officially dry town, as is Dunstable (next door to Groton).
The other Mass dry towns are on Martha's Vineyard or the Berkshires. Most of them are too small to support much business of any sort.
It's a kind of zoning thing nowadays, a way of keeping undesireables out: towns keep out lottery agents or make everyone live on large lots or without a public sewage system for the same reason.
I thought Topsfield and/or Rockport were or are dry. Rockport had something like you could BYOB if you wanted.
An episode of History Channel’s How the States Got Their Shapes showed a restaruant/bar on the Georgia/Tenn. line.
There was a bit of a city/state boundary line dispute. As it is now, booze can be served in one side of the place but not the other since the other town is “dry” and if the boundary
dispute is settled in favor of one particular state the whole
place may go dry.
Wikipedia for Rockport:
>>Except for a period in the 1930s the town remained one of 15 Massachusetts dry towns. The town did remain dry for many years until recently, when it was voted that alcohol could be served at restaurants, but liquor stores are still illegal.