Though the eminent 19th-century American architect Robert Mills conceived the initial design for the Washington Monument, the structure also reflects the technical knowledge and aesthetic judgment of Thomas Lincoln Casey, the Army Corps engineer charged with completing the project. Under Casey, a stagnant construction campaign, emblematic of mid-century political and economic turmoil, at long last produced the tallest building of its day and an enduring American icon.
The monument was erected in two distinct phases, the first one occurring between 1848 and 1858 and the second between 1878 and 1885. The Washington National Monument Society selected Mills' design in 1836, but construction did not begin for another twelve years. An 1848 Congressional resolution permitted the Society to erect the monument on public land within the city, and the Society chose a site near the intersection of the east-west axis through the Capitol and the north-south axis through the White House.
The foundation was laid in June 1848, followed on July 4th by the cornerstone. Progress slowed dramatically in 1854 and halted altogether in 1858. Work resumed under federal direction in October 1878, and a second cornerstone was laid on August 7, 1880. This process of only intermittent progress is reflected in the final appearance of the monument, which features a slight but noticeable change in color partway up, owing to a change in materials. The capstone was set on December 6, 1884, and the monument dedicated on February 21, 1885. Important additions and modifications occurred over the next few years.
Now an iconic emblem of its city, the Washington Monument is a frequent site of events and demonstrations, as well as a popular attraction for visitors from around the world.
DC Inventory: November 8, 1964 (Joint Committee on Landmarks)
National Register: October 15, 1966
This site is included on the Capital City Slavery Tour as the Smithsonian’s National Museum of African American History has released a statement that, according to various sources, construction of the Washington Monument, which started in 1848, involved the use of enslaved laborers. While there is no material evidence (such as receipts, log books, or records of payment) available, it is worth mentioning that any research on the history of slavery is often slow-moving.
For centuries, enslaved persons were viewed as property by slaveholders and the public —and most of their involvement in the physical and cultural construction of the nation has been lost. However, this does not mean that historians cannot make connections based on available information. In relation to the Washington Monument, it is most likely that some form of enslaved labor was used, based on the earlier construction of significant buildings and structures in Washington, such as the White House and U.S. Capitol Building, and the federal government’s acceptance and regular use of enslaved laborers.
Research continues on slavery’s connection to the Washington Monument, as new sources are beginning to be incorporated into the history of slavery, such as descendant testimony, family records, and oral histories. For further information on the role of enslaved laborers in the development of Washington, D.C., view the sources below or explore DC Preservation League's Capital City Slavery Digital Exhibit.