Does anyone remember long ago when a member, I think JR Layman (when he was a member) mentioned that there was a time when the U.S. nearly went to war with Canada over a pig?

He posted it as a kind of guessing game, but I think it was Gregory Matthews who knew it to be true!

That crisis came on June 15, 1859, when an American settler named Lyman Cutlar shot and killed a pig belonging to the Hudson's Bay Company because it was rooting in his garden. When British authorities threatened to arrest Cutlar, American citizens drew up a petition requesting U.S. military protection. Brigadier General William S. Harney, the anti-British commander of the Department of Oregon, responded by sending a company of the 9th U.S. Infantry under Captain George E. Pickett (of later Civil War fame) to San Juan. Pickett's 66-man unit landed on July 27 and occupied a commanding spot near the Hudson's Bay Company wharf, just north of Belle Vue Farm.

James Douglas, governor of the new Crown Colony of British Columbia, was angered at the presence of American soldiers on San Juan. He had three British warships under Captain Geoffrey Hornby sent to dislodge Pickett but with instructions to avoid an armed clash if possible. Pickett, though overwhelmingly outnumbered, refused to withdraw.

Throughout the remaining days of July and well into August, the British force in Griffin Bay (then San Juan Harbor) continued to grow. Captain Hornby, however, wisely refused to take any action against the Americans until the arrival of Rear Admiral Robert L. Baynes, commander of British naval forces in the Pacific. Baynes, appalled at the situation, advised Douglas that he would not "involve two great nations in a war over a squabble about a pig."

http://www.nps.gov/archive/sajh/Pig_War_new.htm