On the continental expansion, Americans pushed Native Americans off their land making deals with them that favored the US more than the tribes. After that, Americans pushed their ideas to the areas being developed trying to make Native Americans abandon their own culture.
On the expansionism overseas the US returned the land to its original inhabitants, this happened in Cuba for example. This was the main difference between expansionism inside and outside the US.
The taking of Hawaii, Puerto Rico, and the Philippines was a violation of fundamental American ideals of self-government and democracy, this was actually the main argument of Anti-Imperialists. Once the US had claimed the territory they established their own rule and define role/impact in each respective country. Conquering other territories and forcing them to abide by American ideals and culture goes against the idea of American freedom.
The War of 1812 was an armed conflict between the United States and the British Empire. ... Since Canada was a British colony back then, Canadians were also British allies. The Americans objected to the British Empire restricting their trade and snatching their sailors to serve on British ships.
