Americans in the early 19th century were, as one foreign traveler bluntly put it, “filthy, bordering on the beastly.” Yet gradually this changed, and today Americans are known for their obsession with cleanliness. This book provides a history of this transformation, from the pre-Civil War era to the 1950s. The book examines the work of early promoters of cleanliness, such as Catharine Beecher and Sylvester Graham; and describes how the Civil War marked a turning point in attitudes toward cleanliness, discussing the work of the U.S. Sanitary Commission, headed by Frederick Law Olmsted, and revealing how the efforts of Florence Nightingale in the Crimean War inspired American women—such as Dorothea Dix, Clara Barton, and Louisa May Alcott—to volunteer as nurses. The postwar efforts of George E. Waring, Jr., a sanitary engineer who constructed sewer systems around the nation and who, as head of New York City's street-cleaning department, transformed the city from the nation's dirtiest to the nation's cleanest in three years, are also included. The book details the efforts to convince African-Americans and immigrants of the importance of cleanliness, examining the efforts of Booker T. Washington, Jane Addams, and Lillian Wald. Indeed, we see how cleanliness shifted from a way to prevent disease to a way to assimilate, to become American. As the book enters the modern era, we learn how advertising for products such as soaps and deodorants showed people how to cleanse themselves and become part of the sweatless, odorless, and successful middle class.