Finally, he challenged Prevost to produce any evidence showing that the treaty framers had intended Rosario Strait.

[7] During this period of disputed sovereignty, Britain's Hudson's Bay Company established operations on San Juan and turned the island into a sheep ranch.

[9] Former Union Army General-in-Chief (1861–1862), George B. McClellan (1826–1885), and George Pickett (1825–1875)’s classmate at the United States Military Academy at West Point, New York and lifelong friend, although military opponent, claimed that General William S. Harney (1800–1889), and Pickett conspired with a cabal, to start a war with Britain (United Kingdom), creating a common enemy, to head off a north–south confrontation.

[10] The theories are given credence when it is noted that later Major General Silas Casey (1807–1882), then a lieutenant colonel and deputy commander of the 9th Infantry Regiment, was reduced to a support role for lower ranked Captain George Pickett who was given independent jurisdiction over a vast area by General William Harney, then a brevet major, and was also passed over by Harney in favor of Captain Pickett when given this choice command.

It turned out that the pig was owned by an Irishman, Charles Griffin, who was employed by the Hudson's Bay Company to run their sheep ranch on the island.

"[11] When British authorities threatened to arrest Cutlar, nearby American settlers called for military protection in the Washington Territory from the United States Army.

[citation needed] Brigadier General William S. Harney (1800–1889), then commanding the military Department of Oregon on the West Coast, initially dispatched then Captain George Pickett (1825–1875), and 66 American soldiers of the 9th Infantry Regiment under Pickett's command, to the off-shore San Juan Island with orders to prevent the British from landing; the regiment sailed aboard the wooden-hulled steamer warship USS Massachusetts.

[2][7][11] Captain Pickett was quoted as saying defiantly, "We'll make a Bunker Hill of it," placing him later in the national limelight reported in the press.

Pickett moved his battery of cannon a few miles north to high ground overlooking both Griffin Bay and the entrance waterway of the Strait of Juan de Fuca to the Puget Sound (and important American new seaport at Seattle in the former Oregon Territory (1848-1853/1859), later split off in the new Washington Territory, 1853–1889), and commenced to build a redoubt for his cannon.

By August 10, 1859, the enlarged defending detachment of now 461 Americans with 14 cannons under Colonel Silas Casey (1807–1882), were opposed by now also reinforced flotilla of five British Royal Navy warships mounting 70 guns and carrying 2,140 men.

[2][7][11] The governor of the off-shore Colony of Vancouver Island, James Douglas (1803–1877), had ordered Captain Hornby to dislodge the American troops, avoiding armed conflict if possible.

When Admiral Baynes finally came later and took stock of the situation, he told Governor Douglas that he would not escalate the conflict into a war between two great nations "over a squabble about a pig".

[17] In September, the 15th U.S. President James Buchanan (1791–1868, served 1857–1861), sent the U.S. Army's General-in-Chief Winfield Scott (1786–1866), to negotiate with Governor Douglas and resolve the growing crisis and prevent it from spinning out of control.

[11] Today the Union Jack flag still flies above the former British Royal Marines camp site, being raised and lowered daily by American National Park Service rangers, making it one of the few places without diplomatic status where U.S. federal government employees regularly hoist the flag of another country, though this is only for commemorative historical and nostalgic purposes.

[19] During the following years of joint military occupation, the small British and American units on San Juan Island had an amicable mutual social life, visiting one another's camps to celebrate their respective national holidays and holding various athletic competitions.

The dispute was peacefully resolved after the initial skirmish of more than a decade of confrontation and military bluster, during which time local British mainland authorities lobbied London to seize back the off-shore islands of the Puget Sound region while the Americans were busy elsewhere with the their own Civil War.

Among the results of the treaty was the decision to resolve the San Juan Island dispute by international arbitration, under the good offices of mediation offered by the newly-crowned German Emperor (Kaiser) Wilhelm I (1797–1888, reigned as King of Prussia since 1861, then as Emperor 1871–1888), chosen to act as arbitrator, meaning that the recently unified German Empire of 1871–1918 (in Germany) would decide if the British or the Americans would officially own the San Juan Islands off the west coast of North America.

[21] German Kaiser Wilhelm I referred the issue to a three-man arbitration commission which met in Geneva, of neutral Switzerland for nearly a year.