Book excerpt: A moving memoir of the beloved fortieth president of the United States, by his son. February 6, 2011, is the one hundredth anniversary of Ronald Reagan's birth. To mark the occasion, Ron Reagan has written My Father at 100, an intimate look at the life of his father-one of the most popular presidents in American history-told from the perspective of someone who knew Ronald Reagan better than any adviser, friend, or colleague. As he grew up under his father's watchful gaze, he observed the very qualities that made the future president a powerful leader. Yet for all of their shared experiences of horseback rides and touch football games, there was much that Ron never knew about his father's past, and in My Father at 100, he sets out to understand this beloved, if often enigmatic, figure who turned his early tribulations into a stunning political career. Since his death in 2004, President Reagan has been a galvanizing force that personifies the values of an older America and represents an important era in national history. Ron Reagan traces the sources of these values in his father's early years and offers a heartfelt portrait of a man and his country-and his personal memories of the president he knew as "Dad."