Canada Feared Invasion
In the end Great Britain chose the course of neutrality because it realized that to do otherwise gambled with the security of its Canadian possessions. Neutrality offered a diplomatic protection for Canada and assured the Northern States that Canada would have no part to play in support for the South.
By 1864, the fear of northern invasion lingered, and as events would show, it was not unfounded. The Union army had grown from a group of hastily recruited civilians into the largest standing army in the world. As General Sir Charles Hastings Doyle observed in a letter to his Canadian commander Sir Fenwick Williams: “They are formidable. If they persevere, they must ultimately succeed.”
And what of the North won and turned its eye to Canada in anger? Or, if the South won its independence and the North turned to Canada for compensation? Hastings Doyle, who was commander of British Troops Atlantic, which included Bermuda, put this to Williams, relating a conversation he’d had with American military commander Ulysses S. Grant and General George Meade during a visit to the siege of Richmond.
“I sympathize with neither side, for they both hate us cordially,” Hastings Doyle wrote. “I used to chafe them a good deal about when they planned to pay you and I a visit. The reply I invariably received was: ‘Oh, we do not have anything to say to you until we have taken Mexico.’ There is but one feeling. Mexico will be theirs when the war with the South is over.”
(Dixie and the Dominion: Canada, the Confederacy and the War for the Union. Adam Mayers, The Dundurn Group. 2003, pp. 52-53)