One of the reasons why there was a need for reform in the US during the mid-1800s is because the US was expanding economically at a rapid pace, as well as expanding to the west, and there was practically no government oversight of growth--which led to people and firms being taken advantage of.
Us victory in the mexican american war in 1848
The war caused the united states to enter another severe depression
the united states became the most richest powerful nation in the world
