Answer for this one here is A.) People are naturally reasonable
hope u have a great day, someone out there luves u , maybe not me, but someone else
Americans were convinced that expansion would boost trade with the Latin America region, help spread democracy and civilization as well as expand the territories.
America increasingly supported expansionism in the late 1800's mainly becasue of the influence of the manifest destiny. In addition, the fashion around at the time was centered around territorial expansions and therefore some Americans felt USA should not be left out. Americans were convinced that expansion would boost trade with the Latin America region, help spread democracy and civilization.
Slavery ended when President Abraham Lincoln delivered his iconic Emancipation Proclamation. This would eventually free black people so they could become ordinary citizens and NOT slaves. So basically, slavery was ended all thanks to good ol' Lincoln :)