Henry Mills Alden was the editor of Harper's New Monthly Magazine--which became Harper's Monthly Magazine in 1900--from 1869 to 1919, a career remarkable for its length but equally remarkable for its vitality, vision, and achievement. During his fifty years at Harper's the magazine helped shape American culture and literature through its encouragement of literary realism, its support of traditional yet distinctly American values, and its discovery of a host of gifted writers and illustrators. Though he remained virtually anonymous to the public, including Harper's readers, he was highly regarded and respected throughout the literary and journalistic establishments. To William Dean Howells, his friend and colleague at Harper's, Alden was "the greatest editor of his time, or almost any time"; to J. Henry Harper, Alden was "the Nestor of magazine editors," one who "naturally stands at the head of the [Harper's] roster"; to the Nation, Alden was one of journalism's...