Delaware is one of the original thirteen colonies and was the first state to ratify the U.S. Constitution on December 7, 1787. Its history includes early Native American tribes, European exploration, and settlement by the Swedes in the 1630s, followed by the Dutch and English. The state played a significant role in the American Revolution and was known for its diverse economy, including agriculture and trade. Throughout the 19th century, Delaware was a key player in the Underground Railroad, helping enslaved people escape to freedom. The state also contributed to the Civil War effort, with many residents serving in the Union Army. Today, Delaware is known for its rich history, including historic sites like New Castle and Old New Castle.