During the Revolutionary War, France became a close friend of Americans seeking freedom from Great Britain. To honor its friendship with America, France gave the U.S. a special gift: sculptor Frederic-Auguste Bartholdi’s beautiful statue called Liberty Enlightening the World.

The Statue of Liberty arrived in New York Harbor on June 19, 1885. It came in 350 pieces packed into 214 crates. The statue was assembled on a pedestal base built by the United States. The 151-foot tall statue has become a worldwide symbol of freedom and democracy.

The Statue of Liberty’s home is Bedloe’s Island (renamed Liberty Island in 1956). From 1892 to 1943, “Lady Liberty” greeted over 12 million immigrants as they arrived on boats at the nearby Ellis Island Immigration Station.

The pedestal of the statue features words from poet Emma Lazarus that reflect immigrants’ hopes and dreams for freedom in America:

Give me your tired, your poor,
Your huddled masses yearning to breathe free,
The wretched refuse of your teeming shore.
Send these, the homeless, tempest-tost to me.

The statue represents Libertas, the Roman goddess of freedom. She holds a torch in one hand and a tablet inscribed with the date of the Declaration of Independence in the other.

Built-in France, the statue is made of hundreds of thin copper sheets assembled on a frame of steel supports. The inner framework was engineered and designed by Gustave Eiffel. He later used the same design on the Eiffel Tower in Paris.

Eiffel’s design allows the Statue of Liberty to move with changes in temperature and wind speed. It also allowed staircases to be built on the inside of the statue. Visitors can climb to an observation deck inside the crown.

The outer layer of the statue is copper that’s only 3/32 of an inch thick — the thickness of two pennies put together. Despite how thin it is, the copper is strong. The amount of copper in the Statue of Liberty could make 30 million pennies!

When the statue was originally assembled, it was a dull brown color, reflecting the natural color of its copper plates. Over the next 30 years, though, it slowly turned to the green color you see today.

What happened? Was it magic? Nope! It was science. A natural weathering process — called oxidation — took place when air and water reacted with the copper plates.

Over time, the weathering of the copper created a thin layer of copper carbonate called a patina. Although some people were worried that the changing color of the statue meant it was decaying, the patina actually protects the copper underneath from further corrosion.

Here are a few interesting facts about “Lady Liberty” you might not have known:

The statue alone stands 151 feet tall.

The pedestal stands 154 feet tall, making the top of the torch 305 feet above ground level.

The statue contains 62,000 pounds of copper and 250,000 pounds of steel. The concrete pedestal weighs 54 million pounds.

Winds of 50 miles per hour can cause the statue to sway up to 3 inches and the torch up to 6 inches.

The 7 points of the crown represent the seven seas and the seven continents.