From Ancestry.com Wiki
Tisbury is a town in Massachusetts. It was formed in 1671 and was previously called Middletowne. It can be found in Dukes county. For more information, contact the county at 51 Spring St., Vineyard Haven 02568. On the attached map, Tisbury is shown as 4 in Dukes county.
For information about the state of Massachusetts see Massachusetts Family History Research.