FactSentinel

The Statue of Liberty was originally a dull brown-copper color when it was dedicated in 1886. The statue's outer skin is made of 300 thin copper sheets, only about 3/32 of an inch thick, which were hammered into shape using a technique called repoussé. When first assembled, this copper had the characteristic reddish-brown shine of a newly minted penny, and early photographs and written accounts from the period confirm this appearance.

The statue's transformation to its now-famous green color occurred gradually over approximately 30 years through a natural chemical process called oxidation. When copper is exposed to oxygen, moisture, and the elements, it forms a protective layer known as a patina. This process, similar to rust forming on iron, involves the copper reacting with carbon dioxide and sulfur compounds in the air to create copper carbonate and copper sulfate compounds, which produce the distinctive blue-green color. By around 1906, newspaper accounts and photographs show the statue had fully transitioned to the green patina recognized today.

A common misconception is that the green color resulted from paint or was somehow original to the statue's design. In reality, the patina was an unplanned natural occurrence, though it proved beneficial: the oxidized layer actually protects the underlying copper from further corrosion, meaning the statue's current color also serves a practical preservation function.