So, here are some different demographics that I'm thinking of putting in this timeline:
1. Because the American Revolution never happens (duh, that's the point of divergence) and thus British loyalists don't settle in Ontario, most of Ontario ends up being settled by French Canadians, with settlers from Metropolitan France and Ireland being added on (Ireland due to the potato famine or something like it). Today, most of Canada's 1867 territory is French speaking (a notable exception is the Niagara Peninsula and shore of Lake Erie, which would've been settled by New Englanders and New Yorkers), and along with the Cajuns in Louisiana the Francophone population of the dominion is around 15-20 million.
Canada in 1867
2. After the British abolished slavery in 1833 (it'd be later ITTL, due to having many more slaves to free and slave owners to compensate), they started importing thousands of Indian indentured servants to the Caribbean, and today there are over 1,000,000
Indo-Caribbeans, including a majority in Trinidad/Tobago, Guyana and Suriname (which was Dutch). So, when the British eventually abolish slavery, they start importing Indian labor to the deep south. Today, a few million people are descended from Indian indentured servants, with the largest populations being in Florida, Louisiana and Texas. This may or may not have been a thing, since India and America are literally as far away as two places can get, but it's definitely something that would have been interesting.
3. East Asian laborers, largely Chinese, Filipino and Japanese, are imported to work in agriculture on the west coast. In our timeline, lots of Japanese and Filipinos worked on sugar plantations in Hawaii, and today Asians are the largest ancestry group in Hawaii. The Pacific coast from Vancouver Island to OTL San Diego would have a large Asian population, especially in the Central Valley of California and Colorado River Valley.