What's its historical significance?
Nootka Sound was first populated by the Nuu-chah-nulth, a name you should recognize from Taboo as the tribe of Delaney's late mother. (Today, the term refers to all the aboriginal tribes of western Vancouver Island, including the Mowachaht, who traded with the sound's first European visitors.) As noted in the intro to John Jewitt's White Slaves of Maquinna, the Nuu-chah-nulth were likely people "who had crossed the Bering Strait about 12,000 years ago."
It's believed that Spanish ships first discovered Nootka Sound as early as 1774, but it wasn't until 1778 that the first documented interaction with the area and its inhabitants took place, when British explorer Captain James Cook bartered for fur with the Mowachaht. "A great many canoes filled with the Natives were about the ships all day, and a trade commenced betwixt us and them, which was carried on the strictest honisty on boath sides," he wrote in his Voyages made in the years 1778 and 1789, from China to the North West Coast of America. "Their articles were the skins of various animals, such as bears, wolfs, foxes, dear, rackoons, polecats, martins and in particular the sea beaver."
The sea otter pelts mentioned reportedly went for $10,000 in Macao -- an insane con, as Cook noted the Mowachaht would trade "anything" for his metals. (Fun fact: The name Nootka was a result of Cook misinterpreting the indigenous people's directions to the sound -- "Nootka, Itchme Nootka, Itchme" -- as its proper name.) Much like in Taboo, several countries sought control of Nootka Sound as a trade post following Cook's success. The sound represented direct access to China and, more specifically, cash money. The main difference between the show and the real history of the area is that it wasn't the Americans and Brits who warred over Nootka; it was (almost) the English and the Spanish.
In 1789, the Spanish sent Esteban Martínez to officially settle the Nootka Sound, seizing ships financed by England's John Meares upon his arrival. The bold move, dubbed the Nootka Controversy, nearly sent the two countries to war, since England claimed Meares had rightfully purchased the land. After three attempts, both countries agreed (in the Nootka Convention) that neither could claim exclusive sovereignty of the area and that Nootka Sound would become a free port.
Though the Delaney Nootka Trading Company drama from Taboo never happened, Nootka Sound remained a popular ("the finest harbor in the world," according to former U.S. Senator Edward A. Hannegan) and contentious asset long after the War of 1812. The Adams-Onís Treaty of 1819, for example, gave Spanish portions of the Pacific Northwest to the U.S. and led to repeat confusion over ownership of Nootka. It wouldn't be until 1846, with the Oregon Treaty, that clear borders were established, ones that ultimately gave Britain (and later, Canada) total control of Vancouver Island.