Pig War Proposed boundaries: Through Haro Strait, favored by the US Through Rosario Strait, favored by Britain Through San Juan Channel, compromise proposal The lines are as shown on maps of the time. The modern boundary follows straight line segments and roughly follows the blue line. The modern eastern boundary of San Juan County roughly follows the red line. Date June 15 -- October 1859 (troops stationed on San Juan Island until 1874) Location San Juan Islands Result Bloodless war -- San Juan Islands awarded to the United States following third - party arbitration. Belligerents United States, Washington Territory United Kingdom, Colony of Vancouver Island Commanders and leaders Colonel Silas Casey, Captain George Pickett Rear Admiral R.L. Baynes Strength 461 combatants, 14 cannon 2,140 combatants; 5 warships mounting 70 cannon
when did the us go to war over a pig
June 15 -- October 1859