The Washington Monument is an obelisk within the National Mall in Washington, D.C., which was built to commemorate George Washington, who served as the Continental Army’s commander-in-chief from 1775 to 1784, and who was the first President of the United States from 1789 to 1797. As the Reflecting Pool and the Lincoln Memorial are located in the northeastern quadrant of the District of Columbia, the Washington Monument, made from marble, granite, and bluestone gneiss, is both the world’s tallest predominantly stone structure and the world’s tallest obelisk, towering 554 feet, 7 11⁄32 inches (169.046 m) tall according to the United States. According to the National Park Service, 555 feet 5 1⁄8 inches (169.294 m) tall was measured by the National Geodetic Survey (measured 2013–14). (measured 1884).
If all monumental columns are measured above their pedestrian entrances, then it is the tallest monumental column in the world. Overtaking the Cologne Cathedral, it was the tallest structure in the world between 1884 and 1889, after which it was then overtaken by the Eiffel Tower in Paris.
The monument was planned to be built in 1848, but it had to be put on hold for 23 years, from 1854 to 1877 because of a lack of funds, an effort to wrest control of the Washington National Monument Society from another organization, and the American Civil War. It was not until after the stone structure was completed in 1884 that work on the interior ironwork, the knoll, and installation of memorial stones was completed.
It is possible to see a noticeable variance in marble shading, visible approximately 150 feet (46 m) or 27% of the way up the shaft, where construction was suspended and then restarted using marble from a different source. The original design was completed by Robert Mills (1781–1855), who was from South Carolina, but he did not include his proposed colonnade because he did not have enough funding, proceeding only with a bare obelisk. The cornerstone was laid on July 4, 1848; the first stone was laid atop the unfinished stump on August 7, 1880; the capstone was set on December 6, 1884; the completed monument was dedicated on February 21, 1885; and the completed monument was officially opened on October 9, 1888.