Modern secularists have been reluctant to recognize Abraham Lincoln's deep spirituality, in spite of the fact that he was often known as "Father Abraham" and has been described as one of the most deeply religious presidents the country has ever seen. Yet for all of his familiarity with the Bible, his invocation of Providence, and of the Almighty, he did not actively participate in a church or lend his name and authority to a denomination. After more than fifty years of hagiographic and contradictory accounts of Abraham Lincoln's life, William Barton stepped boldly into the bedlam of claims and counterclaims about Lincoln's religion. Armed with an enormous collection of Lincoln materials and his own strict evidentiary rules, Barton worked to avoid partisan politicking over Lincoln's legacy and instead to simply "lay bare the facts". To enable a better examination of the vexed questions surrounding Lincoln's faith and religious principles, Barton gathered Lincoln's most important writing and speeches about religion, and topically and chronologically assembled testimonies by his friends, family, and associates, about the most important and most debated issues. This volume, Barton's first and most important work on Lincoln, is introduced by Michael Nelson who provides a history of the literature on Lincoln's religion, the historical context of Barton's writing, and the details of the method that made Barton's approach to this American icon such a distinctive success.