(Sorry for the double post, but inspiration for my home state struck

)
17. Douglas' Dog/The Douglas Dog/The Shenandoah Dog -- Massachusetts
Robert Douglas was an Air Force pilot who spent his summer on Martha's Vineyard, off the coast of Massachusetts. He made three promises to himself: he would build his own boat, he would get a to sail with him no matter the weather, and the Vineyard would be his home.
Douglas did indeed build his own boat, The Shenandoah. His second wish came true when a black lab-boxer mix came aboard his ship in 1967. She was named The Black Dog for the character in Treasure Island. In 1969, the same year Douglas decided to build a tavern on Martha's Vineyard, The Black Dog had a litter of puppies. They all had her black coat and white markings like hers. Douglas gave many of the puppies to friends on the island.
In 1971, the Black Dog Tavern opened. Douglas and The Black Dog herself became more well known on the Vineyard. Souvenir T-shirts were sold featuring The Black Dog on the logo. Some of The Black Dog's puppies were having puppies of their own at this point. Any new puppy born with a black coat was considered one of Douglas' dogs.
By the time The Black Dog died, her descendents were owned by quite a number of families on and off Martha's Vineyard. Enthusiasts of the dogs moved to make them their own unique breed, Douglas' Dog or the Douglas Dog. The breed is also known as The Shenandoah Dog, in honor of Douglas's boat, but the name never caught on due to some people believing the breed had originated in the Shenandoah Valley instead on Martha's Vineyard.
Up until the 1990s, Douglas' Dogs remained obscure, rarely found outside of the Northeast. Then The Black Dog T-shirts became well-known as photographs of celebrities wearing the shirts began being published in national media. For example, President Bill Clinton was photographed in a Black Dog T-shirt while jogging. The Black Dog brand, the breed that had inspired it, truly gained national attention when the Lewinsky scandal broke. It was revealed items from the store had been purchased by Bill Clinton for Monica Lewinsky.
The Black Dog brand exploded to more stores off the Vineyard. Douglas' Dogs became a national breed, with many backyard breeders crossing black labs with boxers and hoping to cash in the breed's popularity.
To protect its status as a unique breed, the breeders of Douglas' Dogs implemented strict standards. All dogs would have to be born black with white markings, but only a certain amount of white in certain areas. Measurement standards based off the original Black Dog are enforced. Douglas' Dogs are expected to be friendly and gregarious dogs that love the water. Most importantly, every Douglas' Dog must have documented descent going straight back to The Black Dog (or at least Vineyard dogs believed to have descended from The Black Dog.)
Although popularity in the breed has waned somewhat in more recent years, Douglas' Dogs enjoy a spike in national attention whenever a Clinton makes headlines.
(Note: My family used to vacation on Martha's Vineyard when I was a little kid. I remember owning a Black Dog t-shirt. The origin story behind the brand and The Black Dog herself are real. So are their connection to the Lewinsky scandal

. I just gave The Black Dog a litter of puppies that took after her. Grainy pictures of the original Black Dog are available on the store's website.)