Gettysburg was, by American Civil War standards, a massive battle. It's importance should not be downplayed. But it is also just a part of a larger mosaic of the war. There was great interest at the time in its outcome, but I doubt you'd find anyone in 1863 that would have called it a turning-point.
Smoke n Booze Duty Free currently has 3 locations, Port Zante Cruise Ship Terminal, Frigate Bay, and the new inbound duty free store at the Robert L Bradshaw International Airport. Smoke n Booze is the first inbound airport duty free store in the Federation, and caters only to arriving passengers.
The nearest major airport is Martha's Vineyard Airport (MVY / KMVY). This airport has domestic flights from Vineyard Haven, Massachusetts and is 1 mile from the center of Marthas Vineyard. Another major airport is Nantucket Memorial Airport (ACK / KACK), which has domestic flights from Nantucket, Massachusetts and is 43 miles from Marthas Vineyard.