This report documents the alterations to the grounds of the United States Treasury building over time and includes recommendations for future landscape treatments. The U.S. Treasury is one of five sites that comprise “President’s Park,” a historically significant setting that is made up of the White House, the Treasury Building, Lafayette Square, the Ellipse, and the Eisenhower Executive Office Building (formerly the State, War, and Navy Building) [Figure 1]. Several extensive histories have already been written on the Classical Revival style Treasury building, and the National Park Service has developed a detailed understanding of the changes that have taken place on portions of the grounds of President’s Park since the late eighteenth century. However, the former deals almost exclusively with the construction and subsequent modifications to the Treasury building itself, with little or no mention of the grounds, and the latter focuses primarily on the White House, Lafayette Square, and the Ellipse. As such, there is at present no definitive landscape history of the U.S. Treasury, although as with the building, the grounds enjoyed a rich, interesting, and distinguished history.The second volume of this report, which includes extensive figures and descriptions, is available through the Historic Preservation Program.