In what way did the end of the Civil War change the way that the states and the federal government interacted?

Prior to the Civil War, the boundary between the Federal Powers and State Powers was very clear. States exercised regulation within their borders and the Federal Government oversaw national issues such as the military and international issues.

However, after the end of the Civil War in 1865, there has been a gradual overlapping of Federal Powers over State affairs. For example, states were granted economic aid during the Great Depression in order to for the country to gain economic stability. The overall tendency throughout the years has been an increase in the Federal Government's power.