Over the course of U. S. history, the federal system has become increasingly "nationalized" in the sense that the federal government’s authority has expanded relative to the power of the states. Which factor has been least important in this development?

living during the great depression had a major affect on the mentality many people. a good portion of people who lived during that time do not trust banks. this is likely the result of the many widespread bank failures in the 30s that caused people to lose their life savings.

i'm not certain but i'm pretty sure it was spanish and portuguese america.

i need this answer                                                                 .