This was the border between Canada and the US 139 years ago, the last time US and British forces came close to fighting. This weekend, those events were commemorated on San Juan Island, now a part of the US, but then the centre of an historic dispute between London and Washington that marked a watershed in the two powers' post-colonial relationship. Britain is sufficiently proud of the event to have paid for a new flagstaff that will fly the Union Jack on a site from which British troops were evicted.
Trouble arose in the last century because these lush, beautiful islands between Vancouver and Seattle, which now draw tourists and wealthy residents from the Pacific North-west, were unwittingly left out of an earlier treaty marking the boundary between Canada and the US. Settlers from both sides arrived, neither recognising the others' government's authority.
The spark came on 15 June 1859, when Lyman Cutlar shot a pig that entered his garden. Mr Cutlar, an American, complained to the Hudson's Bay Company, which ran the farm at the other end of the island. A heated row ensued, and the British authorities tried to arrest Cutlar. America sent a company of the 9th Infantry, which was swiftly matched by three British warships. The Americans refused to withdraw. By 31 August there were 461 Americans with 14 cannons on the island facing five British warships carrying 167 guns and 2,140 troops.
Both sides recoiled in horror when they realised how near they had come to armed conflict over a pig. For 12 years token forces were left in place, until in 1871 the two nations signed the Treaty of Washington. The San Juan question was referred to a man whom both could trust: Kaiser Wilhelm I of Germany. In October 1872 he ruled in favour of America.
To the people who marked the event this weekend with re-enactments and bands, the Pig War is proof of a series of undying certainties of the 20th century: the US-Canadian border is the longest undefended frontier in the world; Britain and America have a "Special Relationship"; the armed forces of Britain and America are closer than any others in the world. But at the time, it did not look that way: in other circumstances, it could - like Britain's reoccupation of the Falkland Islands in 1832 - have become a trigger for long-running conflict.
It was less than a century, after all, since America threw off its colonial chains. The two had fought a bloody and rather pointless war only a few decades before, the War of 1812. The British and the Americans were facing off over the British role in South America and the Caribbean, and had narrowly averted a war over Oregon. Only by 1905 did they finally seal all their differences, and war between the two became unthinkable, says John Beeler, a historian of British naval policy at Alabama State University. As late as the 1890s the likelihood of conflict was "remote, but not impossible", says Mr Beeler. "There were always points of contention."
But by the time the Pig War was resolved, it was clear that America was a rising power, and that Britain faced more serious threats elsewhere: in particular from Germany, the rising European power. It simply did not need conflicts, especially with a fellow English-speaking nation, and a pattern of accommodation to American desires was setting in. In earlier conflicts, Britain's diplomatic representatives and a number of (mainly Tory) politicans had repeatedly argued that any solution was preferable to conflict with the US.
Lord Ashburton, for instance, was married to an American, and had considerable financial interests in America. "What seems most important," he wrote over an earlier border clash, "is that there should be a settlement of some sort, and I do not attach importance ... to the precise terms." At one point he even suggested ceding Canada to the US.
In 1816 John Adams had predicted that "Britain will never be our Friend, till We are her Master". After the American Civil War ended in 1865, even the Spectator had grumpily concluded: "Nobody doubts any more that the United States is a power of the first class, a nation which it is very dangerous to offend and almost impossible to attack." Britain had "clearly and consciously surrendered the mastery of the North American continent to the United States", wrote the historian Kenneth Bourne.
In the mid-19th century, Britain was not in the habit of giving up territory without a fight. Yet the fact that America proved itself master first of North America, then of the hemisphere, was conveniently turned not into a lasting enmity, but into a piece of the mythology of the "Special Relationship". A very convenient use for what was, in fact, a defeat.Reuse content