This past year was the hundredth year that the modern income tax has been collected. No one, critics or fans alike, can deny the importance of this institution in shaping the political landscape of the United States in the twentieth century. One can speculate that the income tax has been the focus of more political energy, both inside and outside Washington, than any other single topic during those hundred years. To mark this anniversary, on April 5, 2013, the Northwestern University Law Review and the Tax Program at Northwestern sponsored a symposium at which the papers in this volume were presented.
