Construction of the Washington Monument resumes in…

Construction of the Washington Monument resumes in 1879 under the direction of Lieutenant Colonel Thomas Lincoln Casey of the U.S. Army Corps of Engineers.

Casey has redesigned the foundation, strengthening it so it can support a structure that ultimately will weigh more than forty thousand tons.

He then follows the society's orders and figures out what to do with the commemorative stones that have accumulated.

Though many people ridicule them, Casey will manage to install most of the stones in the interior walls—one stone will be found at the bottom of the elevator shaft in 1951.

One difficulty that is visible to this day is that the builders are unable to find the same quarry stone used in the initial construction, and as a result, the bottom third of the monument is a slightly lighter shade than the rest of the construction.