Via Andrew Sullivan’s blog, I see that Olmsted is even credited with bringing us that all-American virtue, cleanliness. Katherine Ashenburg wrote about this in her 2008 book, The Dirt on Clean.
Oddly enough it was the Civil War that got Americans interested in being clean. The army’s initially derided Sanitary Commission, headed by the landscape architect Frederick Law Olmsted, had proved that simple soap and water could significantly reduce military mortality, and by the end of the war cleanliness was seen as patriotic, progressive and distinctively American. Good hygiene had other virtues: it was a way to mark status and civility in a country without an aristocracy, and it could “Americanize” the hundreds of thousands of Europeans who began arriving in the 1880s.
Praxis in Landscape Architecture 