The Washington Monument Re-opens.

History On the list of things I always wondered, but not enough to check why.

 Why does the Washington Monument change colour a third of the way up?

The Library of Congress blog explains:

"In 1856, when funding shortages interrupted construction, the monument stood only 156 feet tall out of a projected 500 feet. During the U.S. Civil War, the site was used for the grazing and slaughtering of government cattle, earning it the nickname Beef Depot Monument, as seen in this engraving (below left) [which is in the linked post -- ed.] published in Frank Leslie’s Illustrated Newspaper on Feb. 1, 1862. It was a rather ignominious period for the monument, after the cornerstone had been laid years before on July 4, 1848 to great fanfare in front of 20,000 people, with plans to build a design by architect Robert Mills."

The project was paused for years and then a concerted effort was made to complete the build with a simplified design in time for the centennial.