Though the eminent nineteenth-century American architect Robert Mills conceived the initial design, the structure also reflects the technical knowledge and aesthetic judgment of Thomas Lincoln Casey, the Arm 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, 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 President's House (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. 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.
Built 1848-88 (Robert Mills, architect)
DC Inventory: November 8, 1964
National Register: October 15, 1966