In this first lecture in a series touching on how the U.S. Presidency changed during the 20th century, noted historian Robert Dalek begins with his take on Theodore Roosevelt. In this concise biographical sketch, Dallek describes Roosevelt as the first great president to arrive at the turn of the century, painting the portrait of a charismatic visionary that cast a long shadow on his successor, President William H. Taft. In this introduction, Dallek develops themes that run throughout the course, providing students with an unparalleled view of how modern America was shaped by the men that led it.