As for immigration from Europe, that was how the colonials got there, why wouldn't it have continued?
No successful American Revolution, no French Revolution, no Napoleon, No Congress of Vienna, no European power vacumm, Purssia remains another small Germanic kingdom, No German Empire, No Triple Alliance to counter it, No First World War, No Bolshevik Revolution, No Hitler, No Second World War. Basically it's the situation in the Turtledove/Dreyfuss The Two Georges
It's a world of Empires, the heresy of republicanism never gets a look in. Withour that troublemaker James Monroe spreading dissention south, Spain retains South America.
The British Empire acquires the Ottoman Empire and the Chinese Empire as Protectorates to contain the Russian Empire
The Industrial Revoluition takes place in England on schedule in the 19th Century, but blends into the 20th one in the North American Union dominion, making the British Empire the world's industrial superpower.