You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
alternatehistory.com
Great Britain and the US came close to war several times over the course of the 19th Century, often over border disputes. But which issue or crisis came the closest to starting a war.
P.S. I wasn't sure if I should combine the Aroostook War with the Caroline Affair as they happened so close together and were both kind of resolved as a result of the Webster-Ashburton trade.