An expansionist United States, having just defeated the Confederacy in the Civil War, look to expand northwards and the expense of Britain. To do this they purchase Rupert's Land from the Hudson Bay Company, split British North America in two. This, as intended, angers the British and Anglo-American relations take a sharp downward turn. For practical administrative purposes, Britain creates the new colony of 'Ursalia' from British Columbia and the North-West Territories, although this is only intended as a 'temporary' measure until Rupert's Land is regained from the US. In the meantime, the hostility between Britain and the US is being channelled into a 'biding war' for Alaska, which the Russian Tsar has put up for sale.
Different shades of red indicate different British colonies.