rtHi,
Under The Wilson administration the income tax was instituted and the Federal Reserve System was founded. These were very important changes because it allowed the Federal Government to tax people’s income.
Through the Fed the government can inflate the money supply. Since the foundation of the Fed the dollar lost about 97% of its purchasing power.
Through inflation and the lowering of the interest rates the central bank (i.e. the Fed) is responsible for the boom bust cycles. Hence the Fed caused the Great Depression and the financial crisis of 2008.
Andrew Napolitano has a book coming out later this year on the progressive era:
http://www.amazon.com/Theodore-Woodrow-Presidents-Destroyed-Constitutional/dp/1595553517/ref=sr_1_11?ie=UTF8&qid=1335711069&sr=8-11