<human>:  What is the history of the Washington Monument?
<bot>: The Washington Monument is an obelisk located in Washington, D.C., United States, built to commemorate the first U.S. president, George Washington. Construction of the monument began in 1848, but was not completed until 1888 due to a variety of delays such as financial difficulties, the Civil War, and three design changes. It stands 555 feet high, making it the tallest free-standing masonry structure in the world at the time of its completion. The monument was dedicated on February 21, 1885, and is still one of the most well-known monuments in D.C. and a major tourist attraction.