Native Americans favored the islands for their temperate climate, safe harbors and abundance of resources.

Pioneers, sailors, soldiers and smugglers were the first white men to settle the islands. Various towns have come and gone- including the San Juan town of Argyle and the Lopez Island town of Richardson ­ as time has marched on.

San Juan Island is also known as the Pig War Island. Conflicts between British and Americans came to a head in the so-called Pig War of 1859, resulting in a join military occupation that lasted 12 years. The conflict began when an American settler in San Juan shot and killed a hog belonging to Bellevue Farm, which supported the Hudson's Bay Co.'s fur trapping operations. The settler, Lyman Cutler, killed the hog because it persisted in invading his garden.

The language defining the boundary between Canada and the United States being unclear, and with both nations claiming jurisdiction, U.S. troops were sent to confront British authorities when they attempted to arrest the American settler. British warships appeared off the San Juan coast and a war appeared imminent. Fortunately, cool heads prevailed and the two governments agreed to a joint occupation of the San Juan's until the boundary dispute could be settled. Kaiser Wilhelm of Germany settled the dispute in 1872 in favor of the United States. Wilhelm's decision ended the last territorial conflict between the United States and Great Britain. San Juan Island is the last American soil occupied by Great Britain.

Many of the islands' first buildings and settlements have settled back into the soil, many buildings have been rebuilt or kept up over the years. A number of them are on the same state and national historic registers.

There are two San Juan buildings on the State Register of Historic Places.

• Oddfellows Hall, in Friday Harbor, built in 1892.
• Valley Church, in San Juan Valley on San Juan, built in 1892.

There are four San Juan buildings on the National Register of Historic Places.

• San Juan County Courthouse, the old section, in Friday Harbor, built in 1906.
• Lime Kiln Lighthouse, west side of San Juan, built in 1917.
• Buildings at San Juan Island National Historic Park, at American Camp and English Camp on San Juan, built in the 1860s.
• Roche Harbor Village, north end of San Juan, built in 1881.

For more information, visit the San Juan Island Historical Museum.