Canada in the American Civil War
At the time of the American Civil War, Canada did not yet exist as a federated nation. Instead, the territory consisted of the United Province of Canada (parts of modern southern Ontario and Quebec) and the separate colonies of Newfoundland, New Brunswick, Prince Edward Island, and Nova Scotia, as well as a crown territory administered by the Hudson's Bay Company called Rupert's Land. Britain and its colonies were officially neutral for the duration of the war. Despite this, tensions between Britain and the United States were high due to incidents on the seas, such as the Trent Affair and the Confederate commissioning of the CSS Alabama from Britain.
Canadians were largely opposed to slavery, the preservation of which was one of the main goals of the Confederate States of America, and Canada had recently become the terminus of the Underground Railroad. Close economic and cultural links across the long border also encouraged Canadian sympathy towards the Union. The conservative press in Canada East supported the secession and ridiculed the Yankees as lacking in morality. There was talk in London in 1861–62 of mediating the war or recognizing the Confederacy. Washington warned this meant war, and London feared Canada would quickly be seized.
Trent Affair 
In November 1861 tensions escalated between Washington and London when an American warship stopped the British mail ship RMS Trent on the high seas and seized two Confederate diplomats. London demanded their return and an apology, and to signal its intention to defend its possessions sent 14,000 combat troops to Canada, while the colonials planned to raise 40,000 militia. The crisis ended when President Abraham Lincoln released the diplomats; he did not issue an apology. The British decided that colonial union was now a high priority, as it would relieve London of the need to defend Canada.
Grand Trunk Railway Brigade 
Rising concerns over the security of railways in Canada while the Civil War raged in the United States led to the 1862 creation of the Grand Trunk Railway Brigade. This unit of Canadian Volunteer Militia recruited amongst railway employees had infantry and artillery companies deployed along the railway lines in Canada East and Canada West.
Confederate activity in Canada 
Because of Canada's location and sympathy for the Southern cause, Confederate operators secretly used Canada as a base, in violation of British neutrality, particularly in the Maritimes. The Maritimes' struggle to maintain its independence from Canada, led some Maritimers to be sympathetic to the South's desire to maintain its independence from the North. For example, Halifax merchant Benjamin Wier (1805-1868) acted as Halifax agent for many of the Confederate blockade runners active during the Civil War. In return for ship repair facilities in Halifax, the Confederates supplied him with valuable cotton for re-export to Britain, a lucrative but hazardous course for Wier which required severing his business connections with New England.
On 7 December 1863, while the new Union tug Chesapeake was preparing for service in the South Atlantic Blockading Squadron, 17 Confederate agents disguised as passengers seized it off Cape Cod, Massachusetts. Word of the takeover reached Portland on the morning of 9 December and quickly spread from there. The news prompted federal officials at northern ports along the coast to speedy action.
On 17 December, the recently-captured blockade runner Ella and Annie — which had been hastily manned, armed and sent to sea — finally caught up with the Chesapeake at Sambro, Nova Scotia. Shortly thereafter, the Northern gunboat Dacotah arrived on the scene; and its commanding officer prevented Ella and Annie from taking the recaptured tug back to Boston, lest such action seriously undermine relations between the United States and the British Empire. Instead, to observe diplomatic protocols, he escorted Chesapeake to Halifax where he asked Canadian colonial Admiralty court to restore it to its owner. The Confederate sympathizers were never convicted and the tension arising from the Chesapeake Affair received international attention.
CSS Tallahassee 
On August 18, 1864, the Confederate ship CSS Tallahassee under the command of John Taylor Wood sailed into Halifax harbour for supplies, coal and to make repairs to its mainmast. Wood began loading coal at Woodside, on the Dartmouth shore. Two Union ships were closing in on the Tallahassee, the Nansemont and the Huron. While Wood was offered an escort out of the harbour he instead slipped out of the harbour under the cover of night by going through the seldom-used Eastern Passage between McNab’s Island and the Dartmouth Shore. The channel was narrow and crooked with a shallow tide so Wood hired the local pilot Jock Flemming. The Tallahasse left the Woodside wharf at 9:00 p.m. on the 19th. All the lights were out, but the residents on the Eastern Passage mainland could see the dark hull moving through the water, successfully evading capture.
St. Albans Raid 
The most controversial incident was the St. Albans Raid. Montreal was used as the secret base for a team of Confederates attempting to launch covert and intelligence operations from Canada against the United States. To finance their cause in October 1864, they robbed three banks in St. Albans, Vermont, killed a citizen, and escaped back across the border with $170,000. They were pursued by Union forces over the Canadian border, creating a diplomatic incident. The Canadians then arrested the Confederate raiders, but the judge ruled the raid was an authorized Confederate government operation and not a felony which would permit extradition via the Webster-Ashburton Treaty.
Canadians in the U.S. Army 
The best recent estimates are that between 33,000 and 55,000 men from British North America (BNA) served in the Union army, and a few hundred in the Confederate army. Many of these men already lived in the United States; they were joined by volunteers signed up in Canada by Union recruiters.
Canada refused to return 15,000 American deserters and draft dodgers.
Calixa Lavallée was a French-Canadian musician and Union officer during the American Civil War who later composed the music for "O Canada", which officially became the national anthem of Canada in 1980. In 1857, he had moved to the United States and lived in Rhode Island where he enlisted in the 4th Rhode Island Volunteers of the Union army during the American Civil War, attaining the rank of lieutenant.
Canadian-born Edward P. Doherty was a Union Army officer who formed and led the detachment of Union soldiers that captured and killed John Wilkes Booth, the assassin of Lincoln, in a Virginia barn on April 26, 1865, 12 days after Lincoln was fatally shot. Canadian born Sarah Emma Edmonds was a noted Union spy.
Economic effects 
The Civil War period was one of booming economic growth for the BNA colonies. The war in the United States created a huge market for Canada's agricultural and manufactured goods, most of which went to the Union.
Political effects 
The American Civil War had decisive political effects on the BNA colonies. The tensions between the United States and Britain, which had been ignited by the war and made worse by the Fenian Raids, led to concern for the security and independence of the colonies, helping to consolidate momentum for the confederation of the colonies in 1867.
In this regard, the conflict also had an important effect on discussions concerning the nature of the emerging federation. Many Fathers of Confederation concluded that the secessionist war was caused by too much power being given to the states, and thus resolved to create a more centralized federation. It was also believed that too much democracy was a contributing factor and the Canadian system was thus equipped with checks and balances such as the appointed Senate and powers of the British appointed Governor-General. In reaction a guiding principles of the legislation which created Canada – the British North America Act was peace, order, and good government. This was a collectivist antithesis to American individualism that became central to Canadian identity.
See also 
- Jones, Preston. "Civil War, Culture War: French Quebec and the American War between the States" (2001)
- Bourne (1961)
- Morton (1964) 102-3
- Greg Marquis. In Armagedon's Shadow: The Civil War and Canada's Maritime Provinces, (1998) McGill Queens Press, p. 233
- Dennis K. Wilson, Justice under Pressure: The Saint Albans Raid and Its Aftermath(1992).
- Danny R. Jenkins, "British North Americans who fought in the American Civil War, 1861–1865," (MA thesis, U. of Ottawa, 1993), online edition. Note that Robin W. Winks does not make any estimates in his "The Creation of a Myth: 'Canadian' Enlistments in the Northern Armies during the American Civil War," Canadian Historical Review 1958 39(1): 24–40.
- John Herd Thompson and Stephen J. Randall, Canada and the United States (4th ed. 2008) p. 37
- Canadian MoH recipients of the American Civil War
- "American Civil War" The Canadian Encyclopedia.
- Patrick James (2010). Constitutional Politics in Canada After the Charter: Liberalism, Communitarianism, and Systemism. UBC Press. p. 55.
- Adams, Ephraim Douglass. Great Britain and the American Civil War (2 vol. 1925)
- Bourne, Kenneth. British Preparations for War with the North, 1861-1862. The English Historical Review Vol 76 No 301 (Oct 1961) pp 600–632
- Bovey, Wilfrid. "Confederate Agents in Canada During the American Civil War," Canadian Historical Review 1921 Vol. 2, Number 1 Pages 46–57
- Ferris, Norman B. Desperate Diplomacy: William H. Seward's Foreign Policy, 1861. (1976) 265pp.
- Hubbard, Charles M. The Burden of Confederate Diplomacy (1998) 271pp
- Jenkins, Brian. Britain and the War for the Union. (2 vol 1974), by a Canadian scholar
- Jenkins, Danny R. "British North Americans who fought in the American Civil War, 1861-1865," (MA thesis, U. Of Ottawa, 1993), online edition.
- Jones, Howard. Abraham Lincoln and a New Birth of Freedom: the Union and Slavery in the Diplomacy of the Civil War, (1999)
- Jones, Preston. "Civil War, Culture War: French Quebec and the American War between the States," Catholic Historical Review. Volume: 87. Issue: 1. 2001. pp 55+ online edition
- Kazar, John D. "The Canadian View of the Confederate Raid on Saint Albans," Vermont History 1964 (1): 255-273,
- Macdonald, Helen Grace. Canadian Public Opinion and the American Civil War (1926)
- Marquis, Greg. In Armageddon's Shadow: The Civil War and Canada's Maritime Provinces. McGill-Queen's University Press, 1998
- Morton, W.L. The Critical Years: The Union of British North America, 1857-1873 (1964)
- Owsley, Frank Lawrence. King Cotton Diplomacy: Foreign Relations of the Confederate States of America (1931)
- Stouffer, Allen P. "Canadian-American Relations in the Shadow of the Civil War," Dalhousie Review 1977 57(2): 332-346
- Wilson, Dennis K. Justice under Pressure: The Saint Albans Raid and Its Aftermath (1992). 224 pp.
- Winks Robin W. Canada and the United States: The Civil War Years. (1971).
- Wrong, George M. (1968). Canada and the American Revolution: The Disruption of the First British Empire, Rowman & Littlefield Publishers.
- Canada Civil War Association
- "American Civil War" The Canadian Encyclopedia.
- Canadians in the American Civil War