67th Tigers
Banned
The Indian Armies are unlikely to be used in such an intervention, though, unless they want yet another risk of mutiny on their arms; the Sepoy rebellion is not exactly far at this point and I very much doubt the british would want to risk it, especially considering they'd be fighting for a country that has a rather dim view of dark-skinned people (hell, if anything could encourage the radical abolitionists to try to influence Lincoln even more it could be that). Deploying from Canada? Do the Indian troops even have winter gear? I know Egypt is a whole other country, but when the Ottoman-Egyptian wars happened, this ended up being one of the major things that bogged down the egyptian offensives in the north: they lacked warm enough clothing and their troops died from it even in the rather mild Syrian and Cilician winter (still goes around -5 to 5 for a couple of weeks).
And if the indian armies get involved, expect the state militias to fight, unlike IOTL, even if both sides end up with record desertion rates.
The navy still has the advantage, to a certain point, but a navy alone doesn't win a war against a country that's not dependent on trade for the survival of its people; sure it is for some of its wealth, but the union won't starve from a blockade.
The planning was for a 30,000 man Anglo-Indian expeditionary force to remove the west coast from the United States.
The force going to Canada and the Maritimes was 85,000 European regulars. There are 60 infantry battalions either in Canada or available for deployment to Canada. An infantry battalion is the bayonet strength of a typical ACW brigade. The available regular force for Canada has more bayonets than the entire realistic disposable force the Union has for operations against the CSA and Canada.