The Washington Monument is an obelisk on the National Mall in Washington, D.C., built to commemorate George Washington, once commander-in-chief of the Continental Army and the first American president. Standing almost due east of the Reflecting Pool and the Lincoln Memorial, the monument, made of marble, granite, and bluestone gneiss, is both the world's tallest stone structure and the world's tallest obelisk, standing 554 feet 7 11⁄32 inches (169.046 m) tall. It is the tallest monumental column in the world if all are measured above their pedestrian entrances, but two are taller when measured above ground, though they are neither all stone nor true obelisks.
Construction of the monument began in 1848, and was halted from 1854 to 1877 due to a lack of funds, a struggle for control over the Washington National Monument Society, and the intervention of the American Civil War. Although the stone structure was completed in 1884, internal ironwork, the knoll, and other finishing touches were not completed until 1888. A difference in shading of the marble, visible approximately 150 feet (46 m) or 27% up, shows where construction was halted and later resumed with marble from a different source. The original design was by Robert Mills, an architect during first half of the 19th century, but he suspended his colonnade, proceeding only with his obelisk, whose flat top was altered to a pointed marble pyramidion in 1884. The cornerstone was laid on July 4, 1848; the first stone at the 152-foot level was laid August 7, 1880, the capstone was set on December 6, 1884, and the completed monument was dedicated on February 21, 1885. It officially opened October 9, 1888. Upon completion, it became the world's tallest structure, a title previously held by the Cologne Cathedral. The monument held this designation until 1889, when the Eiffel Tower was completed in Paris, France.
The monument was damaged during the 2011 Virginia earthquake and Hurricane Irene in the same year and remained closed to the public while the structure was assessed and repaired. After 32 months of repairs, the National Park Service and the Trust for the National Mall reopened the Washington Monument to visitors on May 12, 2014.(Wikipedia)
"The Washington Monument"