Fr. Samuel Mazzucchelli, OP was one of great evangelists of the central United States during the middle of the 19th century. His life is bound up with the larger story of the Order of Preachers (i.e. the Dominicans), which he was a member of. This preacher, translator, and architect gave up the world he knew in Italy to travel to the new world to proclaim the Gospel and administer the sacraments. This book does two things. First, it details the life of Fr. Samuel and historical context in which he and the Order of Preachers worked in the first half of the 19th century on both sides of the ocean. Secondly, it provides translations of previously unpublished documents that shed light the subjects of this book.