Despite these developments the aluminum capstone remains in place today and is considered to be in good shape. After the completion of the monument D.C. Building Code was updated to state that the Washington Monument is to be the tallest structure in the city, no future buildings can surpass its 555 feet.

Yes, the very tip of the Washington Monument is capped with a small pyramid of solid aluminum. When it was placed on December 6, 1884, aluminum was a rare and precious metal, valued similarly to silver because it was extremely difficult to extract and process before the invention of the Hall-Héroult process. The 100-ounce cap served both a decorative purpose and a functional one as the terminal for a lightning rod system. Over the years, the cap has been struck by lightning numerous times, which has slightly blunted its sharp point and caused some minor pitting. During various restorations, most notably after the 2011 earthquake, engineers inspected the cap and found it remarkably intact. While the monument itself is made of marble, granite, and bluestone gneiss, that small piece of aluminum remains one of the most historically significant parts of the structure, representing the peak of 19th-century metallurgical technology. It is inscribed with names and dates of the construction, though these are invisible to the public looking up from the ground.