This first full-length biography of Alton Brooks Parker provides an in-depth look into the life, career, and legacy of one of the most important New Yorkers of the Gilded Age. Parker had the courage to challenge Theodore Roosevelt for the presidency in 1904--at the height of Roosevelt's popularity--and was a transition point between the conservative and the new, progressive wing of the Democratic Party. Based on new archival research, this book contributes to our understanding of how political campaigns were conducted during the Gilded Age/Progressive Era, in comparison to modern campaigns. It also provides insights into the changing Democratic Party as it transformed from the presidency of Grover Cleveland to the presidencies of Woodrow Wilson and Franklin D. Roosevelt.