When Horace Greeley published his famous imperative, “Go West, young man, and grow up with the country,” the frontier was already synonymous with a distinctive type of idealized American masculinity. But Greeley’s exhortation also captured popular sentiment surrounding changing ideas of American boyhood; for many educators, politicians, and parents, raising boys right seemed a pivotal step in securing the growing nation’s future. This book revisits these narratives of American boyhood and frontier mythology to show how they worked against and through one another—and how this interaction shaped ideas about national character, identity, and progress.