Rhode Island
The boundary between Massachusetts and Rhode Island has been one of the poorest defined and most contentious of all state borders.  A royal decree in 1746 moved the border east of Narragansett Bay by three miles, transferring the present day towns of Barrington, Bristol, Little Compton, Tiverton and Warren from Mass to Rhode Island.

Ongoing battles continued well into the 19th Century, with final resolution coming from the Supreme Court in 1862, which transferred modern-day East Providence to Rhode Island as well.

Mass 351 will pass through all of these towns as part of its Pan Rhode Island riding.