When you think of symbols of the United States, you probably think of the bald eagle, Mount Rushmore, or Old Glory itself (and these incredible American flag photos will immediately make you feel patriotic). But the symbol that quite literally stands, more than any other, for freedom and refuge stands in New York Harbor: the Statue of Liberty. Imagining Lady Liberty immediately creates a mental picture: her massive 305-foot stature; her majestic crown and torch; her bluish-green color. However, it turns out that she was not designed to be green, nor was she always that color.
The Statue of Liberty was given to the United States in 1885 as a gift from the people of France. She was built over several years out of the decidedly non-green material copper (over 30 tons of it!). So how did she become green? (Related: learn about the process of cleaning Lady Liberty here.)
It has nothing to do with paint (or jealousy). The statue’s green color comes from several chemical reactions. The American Chemical Society made a video breaking down each stage of the statue’s chemical transformation. It turns out that the Statue of Liberty has actually been multiple different colors.
As the name of the material would suggest, the statue was originally a bright copper color. However, once she was assembled in New York harbor, a reaction called oxidation—which is also responsible for rust—began. Her copper exterior began to react with the oxygen in the air. That reaction created tenorite, a dark brown-black material. So her copper color got darker before it got lighter.
Tatiana Ayazo/Rd.com, shutterstock
Completing the chemical makeover, sulfuric acid in the air (much of which comes from New York air pollution) reacted with the tenorite and the oxidized copper, turning the exterior green. By 1906, all traces of copper were gone and the statue was the color we know today. However, in the early 1900s, Congress collected money for repairs, suggesting that the statue be painted its original copper color—but people protested, and the “repairs” never happened. Thankfully, because we certainly can’t imagine this iconic statue being any other color. Plus: learn why American money is green.
But with all of these reactions, will the Statue of Liberty be changing color again any time soon? Will we see a purple Statue of Liberty? Luckily, no. The statue’s exterior is finally “stable,” meaning it’s not reacting anymore. Green will continue to stand for liberty for generations to come. Here are 20 more fascinating facts about the Statue of Liberty.