The Washington Monument is a large, tall, white obelisk near the west part of the National Mall in Washington, D.C. It was built to remember George Washington, who was the first President of the United States. It is the tallest stone structure in the world, and is 555 feet 5⅛ inches (169.294 m) tall. The monument is made of marble, granite, and sandstone. The monument was started in 1848 but was not finished until 1884. This was because the American Civil War started soon after construction started. Construction continued after the war ended, but the type of sandstone was changed. Because of this, about part of the way up, you can see a change in color of the monument. The monument opened on February 21, 1885 after 19 years total of construction. 