INTRODUCTION. The incidents, manners and customs of frontier life in the country once called the "Far West,"-now the valley of the Mississippi, are interesting to all classes. The religious events and labors of good men in "works of faith and labors of love" among the early pioneers of this valley, cannot fail to attract the attention of young persons in the family circle, and children in Sabbath schools. The author of this work, as the commencement of a series of PIONEER BOOKS, has chosen for a theme a man of singularly benevolent and philanthropic feelings; peculiarly amiable in manners and social intercourse; with habits of great self-denial; unusually disinterested in his labors, and the first preacher of the gospel who ventured to carry the "glad tidings" into the Spanish country on the western side of the GREAT RIVER.1 The writer was intimately acquainted with this venerable man, who, by all classes, was familiarly called "FATHER CLARK," and induced him to commence sketches for his own biography. His tremulous hand and enfeebled powers failed him soon after he had gotten to the period of his conversion, while a teacher in the back settlements, and he was unable to finish the work. By correspondence and personal interviews with many who knew Father Clark, and from his verbal narratives in our interviews for many years, the writer has been enabled to give a truthful sketch of the most important incidents of his life. While seriously disposed persons of every age and station may derive pleasure and profit in contemplating the moral portraiture given, it is to the young reader, more especially, the author dedicates the memoir of FATHER CLARK.