The Statue of Liberty (French: Statue de la Liberté), officially titled Liberty Enlightening the World (French: La liberté éclairant le monde), is a monument that was presented by the people of France to the United States of America in 1886 to celebrate its centennial. Standing on Liberty Island in New York Harbor, it welcomes visitors, immigrants, and returning Americans traveling by ship. The copper-clad statue, dedicated on October 28, 1886, commemorates the centennial of the signing of the United States Declaration of Independence and was given to the United States by France to represent the friendship between the two countries established during the American Revolution. Frédéric Auguste Bartholdi sculpted the statue and obtained a U.S. patent for its structure. Maurice Koechlin—chief engineer of Gustave Eiffel's engineering company and designer of the Eiffel Tower—engineered the internal structure. Eugène Viollet-le-Duc was responsible for the choice of copper in the statue's construction and adoption of the repoussé technique, where a malleable metal is hammered on the reverse side.