For hundreds of years, city planners have developed parks, planted trees and set aside open space in urban environments. Boston Common, a public square used for grazing livestock since 1634, was converted into a park in 1830. A quarter of a century later, New York’s Central Park opened, designed by Frederick Law Olmsted and Calvert Vaux. Olmsted, originally a journalist by trade, went on to develop parks throughout the United States, including in Wisconsin, Colorado, Washington, Georgia and the District of Columbia.