Naval History and Heritage Command

Naval History and Heritage Command

The San Juan Island Boundary Dispute, 1859: Conditions for Peace and Maritime Superiority in a Very Gray Zone

J. Overton

This essay is a selected submission from the 2017 CNO Naval History Essay Contest. The content of the original essay has been copyedited prior to publication.


The 1859 San Juan Island Boundary Dispute, now more commonly called the Pig War, is referenced mostly as a military anomaly and interesting local history footnote. [1] Two great nations nearly went to war in a remote part of the Pacific Northwest over something as minor as a murdered pig, but cooler heads prevailed and everyone lived happily ever after (except, of course, for the aforementioned pig).

The Dispute, however, is a classic example of operations in a Gray Zone, that area described as the “… dominant form of state-to-state rivalry in the coming decades.” [2]  This particular Zone, like some of today, involved conflicts over land which could only be settled by operations at sea. Within this Gray Zone one actor managed to establish and maintained maritime superiority without resorting to violence, and over time, to achieve a favorable end state. The lasting relevance of this event thus deserves further study.

An examination of the Dispute’s operating environment reveals certain conditions that helped facilitate both the weaker power’s maritime superiority and the eventual peaceful resolution to this international crisis. These same conditions can have similar effects in contemporary and future Gray Zones.

“…Between the traditional war and peace duality.”


 “The Sovereignty Remains Avowedly in Dispute.”[6]

While the concept and terminology of the Gray Zone is new, the geo-political situation it described is not, and the United States (U.S.) military does have experience operating within them. During the 1840s and 50s, U.S. joint forces operated alongside, and against, many disparate parties in the Puget Sound area of the Pacific Northwest. These operations culminating in direct competition with another Nation state over control of maritime boundaries and islands.



In 1854, in response to requests from the Washington Territorial government, U.S. Navy and Revenue Marine (a forerunner service of the U.S Coast Guard) ships began making regular patrols in Puget Sound and adjoining Strait of Juan de Fuca to guard against Northern Indian raids. By 1855, all existing branches of the U.S. military, as well as local territorial militia units and interagency partners like the U.S. Lighthouse Service and Coastal Survey, were operating regularly in and around the Puget Sound littoral.[9] The Royal Navy also maintained a presence in and around Vancouver Island, with much the same general mission as U.S. forces, and the Hudson’s Bay Company, a quasi-governmental British corporation, operated its own forts and vessels in the area.

Between1855-56 a confederation of local Indians resisted a series of reservation-forming treaties and fought against local settlers, the U.S. Army and Navy, and local militia. Navy and Revenue Marine officers engaged in several pitched battles that included a naval bombardment to save the tiny village of Seattle, and some land engagements that extended east of the Cascade Mountains before fighting ceased.[10] Simultaneously and independently, Northern Indians threatened mariners and isolated settlements, and fought a battle with U.S. Navy Sailors and Marines near the logging town of Port Gamble. British and American settlers and forces alternated between quarrels, disagreements, and cooperation during these hostilities. Americans fueled tensions when they poured into British Columbia, usually without the government’s permission, seeking fortune after gold strikes. These events challenged British security and sovereignty in the region, and prompted the stationing of more Royal Navy ships in the area, and making British Columbia a British colony in 1858.[11] By then, all the elements of a Gray Zone were evident here: ambiguity about the nature of competition and conflict, “opacity of the parties involved and uncertainty about the relevant policy and legal frameworks,” ambiguity about the role of military forces and the ultimate objectives sought, and rival national powers seeking to either maintain or upend the status quo.[12]


On June 15, 1859, one of these Americans shot a pig owned by the Company, which he found trespassing in what he believed was his rightfully-owned garden. British authorities threatened to arrest him, and consequently, to forcibly evict all American settlers from the Island. The Americans on San Juan brought the matter up with the commander of the U.S. Army’s Department of Oregon, General William Harney, while he visited on a regular patrol of Puget Sound settlements aboard the Army ship Massachusetts. Harney, a veteran of the Mexican War and several Indian wars, responded to their concerns by sending Captain George Pickett and a company of soldiers over on Massachusetts from their fort in nearby Bellingham, Washington. They were based there originally to protect settlers against Northern Indian raids, and would ostensibly to do the same for Americans on San Juan Island. Pickett landed on July 27, 1859, and began building fortifications and attempting to enforce American laws on the disputed island, actions well beyond those needed if the intent was purely Northern Indian defense.[14] When Vancouver Island governor, James Douglas, learned of what his government believed was an invasion of their sovereign territory, he sent British warships to coerce or dislodge Picket’s company, ideally without resorting to force.[15] 

For three tense months, two countries, one the world’s largest empire and greatest naval power and one a rising revisionist nation, faced off and very nearly began their third war against one another. [16] Five conditions facilitated both the weaker party’s effectively gaining maritime superiority, even without their actual Navy vessels in theater, and exploiting that gain to ultimate advantage without firing a shot in anger.

Presence Was More Important Than Capability

In 1859, U.S. land forces in the Puget Sound region consisted of a few small scattered forts equipped and positioned to defend American settlements against Northern Indian raids. Seagoing forces consisted of a few small, scattered vessels of the Revenue Marine, Lighthouse Service, Coast Survey, U.S. Army Quartermaster Corps, and various merchant ships, armed if at all to defend themselves against Northern Indians in canoes. [17] Approximately 2,000 U.S. Army soldiers were in the Pacific Northwest, but the force assigned to San Juan Island had at most 100 troops, two small cannon, and the occasional use of ships Massachusetts, lighthouse tender Shubrick, and mail carrier Julia.

By contrast, British forces, based in the developing installation of Esquimalt on Vancouver Island, had five seagoing warships, totaling 167 guns, all within a few hours sail or steam from San Juan Island. [18] The initial force sent by Douglas to confront Pickett consisted of three of those ships and nearly 1,000 troops, mostly sailors but also 46 Royal Marines and 15 engineers, a useful group for taking and holding ground. [19] The British had the obvious advantage by all traditional measures, yet they were ultimately deterred by the tiny U.S. force. [20] 

Whatever military capabilities were on display, both sides expressed concern that the beginning of an actual kinetic conflict would quickly involve more forces than were arranged on and around the island.  Neither side could decisively attack the other’s Center of Gravity because neither had one in this theater, and both sides knew that a war for this little Island would soon stretch far beyond Puget Sound. Despite the aggressive nature of principals like Harney, Pickett, and Douglas, a quick and decisive victory was unobtainable by either nation-state belligerent.

In this Gray Zone, the very presence of the opposing joint forces, however weak, represented the entirety of the will and means of their respective countries, and hence served as an effective deterrent. As long as maritime operations didn’t involve kinetic violence with the opposing British force, the U.S. forces, even with no actual naval vessels, had at least maritime parity with the Royal Navy.

Mutual Threats Necessitated Cooperation

In the preceding decade, despite numerous confrontations between Americans, British, local natives, and northern Indians, no group collectively regarded any of their adversaries as absolute enemies. The northern Indians were the group most feared by all others, although still not seen as a scourge to be wiped out. [21] Even as the British naval cannons were trained on the small American camp on San Juan Island, relations between the opposing commanders and troops of these two nations were surprisingly cordial. Officers on both sides invited one another to picnics and dinners, and attended church together. [22]

This condition, lacking deep cultural hatreds or vengeance-seeking for past wrongs, and maintained by the isolated and difficult nature of the area, facilitated tolerant coexistence. It also necessitated the two participating nation-state forces cooperating against mutual threats and for mutual gain. Rather than enemies, in this Gray Zone, the parties treated each other as competitors, or what would now be called “actors of concern,” and rather than allies, joined with one another when convenient.

Interagency partners, not always under direct control of their respective countries’ military, could find aligned interests and threats on which to operate. British and American civil magistrates appointed to the island agreed, informally, to work together to enforce laws against crime and vice during the dispute period. [23]

Within this Gray Zone, there were no absolute enemies or permanent allies, and the two most dominant actors had more to fear from outside actors and elements than they did from one another. At times, both countries would need one another exercise some form of effective maritime operation, and again, the fledgling U.S. force had effective maritime parity with its more robust British cousin.

Rational Actors were Influenced by Other Conflicts

Although both U.S. and British Forces in the Northwest had been involved in several “small wars,” lessons of the state-on-state Crimean and Mexican wars were such pervasive factors that they became actual conditions in this operating environment.

British officers were aware of their recent war against near-peer adversaries in the joint warfare of the Crimea, a series of horrific operations for dubious reasons that caused tremendous casualties for unclear goals. Some soldiers, sailors, senior officers, and political actors even had the War of 1812 in mind during this Gray Zone. That war had resulted in much damage and little gain for both belligerents, although the smaller and less experienced U.S. Navy had managed to do more damage than its size and experience probably warranted.[24]

Harney and Picket were veterans of the Mexican War, which yielded far better results for the U.S. than did the Crimean War for Great Britain. But there would be little hope that this time, after the fighting broke out, an American expedition would march on the enemy capital, dictate surrender terms, and increase U.S. territory by one third its previous size.

Other immediate security concerns took precedent even during the tensest days of the dispute. The Northern Indians remained more feared than the British by American military and settlers.[25] A potentially-threatening band of Washington Territory Native Americans caused panic and prompted request for military assistance from the ships supporting Pickett’s encampment, and both Shubrick and Massachusetts were involved in Indian policing duties in other parts of the Sound during the Dispute months.[26]



Operational Forces were De Facto Policy Makers



Those on scene, with the most to lose should war break out, had already shaped the environment such that conditions were set for reasonable resolution to the dispute once politically-designated policy makers arrived. For varying combinations of the conditions mentioned above, U.S. joint and maritime forces did not need “4.5 acres of diplomacy” inherent in a Nimitz-class nuclear power aircraft carrier to conduct operations at desired times and places and pursue what they saw as the best interest of their nation.

Ambiguity Favored the Revisionist


Ambiguity, the “defining characteristic” of a Gray Zone, served the purpose of omitting a clear military objective or desired end-state by any actor. [31] It also gave an advantage to the revisionist power. Dominant powers, particularly those as globally-engaged as 19th century Great Britain, have a variety of dispersed interests, most far greater than that of a small island with minimal resources or strategic value. The revisionist power, here the younger United States, had far fewer interests, with less to lose, and more to gain proportionately. Typically, the greater power retains the right to draw boundaries, impose culture, and write history. Gray Zone conflicts, however, make the stakes appear insignificant for the greater power and critical for the lesser power. While seemingly being able only to hold its own in this maritime environment, by simply being able to stay on a contested piece of land, whatever its value, and operate to support that force, the weaker power had seized the initiative and gained effective maritime superiority.  

Many Shades of Gray

Scott’s proposal was implemented within months. In 1860, a group of Royal Marines landed on the island’s north end, and an equal-sized detachment of U.S. Soldiers consolidated farther south. Pickett left, then returned to command the U.S. detachment for some months until the outbreak of Civil War and his decision to side with the Confederacy.

Joint occupation lasted until 1872. During those intervening years, ships of the U.S. and Britain resupplied their respective country’s garrisons on the Island and for the most part continued cooperating when their interests aligned. The boundary issue was submitted to third part arbitrators in Europe, who deemed the northwestern Haro Straight channel as the correct maritime boundary, and thus made San Juan Islands were officially recognized as U.S. territory. [32] Much transpired during the years of joint occupation: the U.S. conducted its most destructive war, the northern Indian and native threats in the Puget Sound had been diminished, and the Dominion of Canada had been granted self-governance. The Puget Sound area, while still a wilder corner of North America, was no longer a Gray Zone.

The revisionist actor had retained their effective maritime superiority and “won,” if this victory can be claimed as such, the Pig War. Aspects of the global distribution of power were changed in their favor, and they had achieved this without resorting to actual warfare. [33] But this victory yielded less-than stellar gains. Within months of the Royal Marines leaving the Island, the U.S. military left as well. San Juan Island never supported another large military presence, and was never especially important to sea lanes or border control. Today it is a tourist destination known for its rural beauty, whale watching, and National Park sites at the old British and American camps. The Royal Canadian and U.S. navies both maintain sizable forces in the Puget Sound and Strait of Juan de Fuca areas, and both cooperate regularly in operations ranging from search and rescue to undersea weapons’ testing to oil spill response. The prospect that these two great nations almost went to war here, over a pig or over a maritime boundary, seems absurd.


(This essay was published in the U.S. Naval Institute's Naval History Blog.)


[1] Gordon Robert Lyall. “From Imbroglio to Pig War: The San Juan Island Dispute, 1853-71, in History and Memory.” Journal of B.C. Studies, #186 (2015): 73- 93.

[2]   Michael J. Mazarr.  Mastering the Gray Zone: Understanding a Changing Era of Conflict.  (Carlisle, PA: U.S. Army Strategic Studies Institute, 2015), 2.

[3]  “The Gray Zone” U.S. Special Operations Command White Paper, 1, available at

[4]  David Barno and Nora Bensahel. “Fighting and Winning in the Gray Zone” available at

[5] Mazarr Mastering the Gray Zone, 2.







[12] Mazarr Mastering the Gray Zone, 2 and “The Gray Zone” 1.

[13]  “The Pig War,” San Juan Island National Park.


[15] Vouri, Pig War, 99-114.

[16] “The Pig War,” San Juan Island National Park.


[18] Vouri, The Pig War, 99-114.

[19] “The Pig War,” San Juan Island National Park.





[23] Vouri, The Pig War, 130-153.

[24] British Admiral Baynes had served in the War of 1812 and the Crimean War.


[26] Puget Sound Herald, Aug 19, 1859, 2, “Doings Below” available at

[27] Murray, The Pig War, 41.



[30] Puget Sound Herald, Aug 19, 1859, 2, available at


[32] The Pig War,” San Juan Island National Park.


Published: Mon Jan 28 12:24:30 EST 2019