Polk was in favor of acquiring both Texas and Oregon because he was a firm believer in manifest destiny. ... This belief that it was inevitable that this land would belong to the US prompted the federal government to acquire lands like Texas and Oregon.
The French-Indian was extremely costly. It left Britain with a huge debt. The British thought the colonists were to pay the debt because they were defending the colonies from the French. Britain also maintained a standing army in American colonies which was a huge financial stress. As a result, Great Britain taxed the colonies.
The North didn’t believe in slavery and the south did. The constitution divided them because they both believed in different things. In the South there was more plantations so they needed slaves to keep up the production when the North was cold and didn’t need much help on plantations.