The internal structure of the Statue of Liberty is cast iron and stainless steel, but the outside is copper that runs about 2.5 millimeters thick. The copper coating is the same width as two U.S. pennies stacked on top of each other.
The Statue of Liberty is 305 feet and 1 inch from the ground to the tip of the flame, which is the same height as a 22-story building. She was the tallest structure when she was first erected in 1886. At that time, Lady Liberty was more of a brown copper color, like the American penny but, in time, the copper oxidized and turned blue-green, the color she became known for. It took about 30 years for that oxidation to set in and change the color of the statue completely. Lady Liberty takes after the Roman goddess of Liberty, which is why she is in female form.