Indians first entered what is now Delaware several thousand years ago, probably in search of game. At the time of European exploration in the 17th century, the region was populated mainly by the Lenni-Lenape (or Delaware) Indians, an Algonquian-speaking people who numbered about 11,000.
| Important dates in Delaware | |
| 1609 | English explorer Henry Hudson, sailing for the Dutch, visited Delaware Bay. |
| 1610 | A ship commissioned by Lord De La Warr, governor of Virginia, entered Delaware Bay. |
| 1631 | The Dutch founded Zwaanendael at present-day Lewes. |
| 1638 | Swedish colonists founded the colony of New Sweden. They established Fort Christina, Delaware's first permanent settlement, at present-day Wilmington. |
| 1655 | The Dutch captured New Sweden. |
| 1664 | The English seized Dutch territory on the Delaware River. |
| 1682 | William Penn took over the Delaware counties. |
| 1704 | Delaware's first separate legislature met. |
| 1777 | The British invaded Delaware and won a small battle at Coochs Bridge. |
| 1779 | Delaware signed the Articles of Confederation. |
| 1787 | (Dec. 7) Delaware became the first state of the Union. |
| 1802 | Eleuthere Irenee du Pont founded a powder mill on the banks of Brandywine Creek. |
| 1861-1865 | Delaware fought on the Union side during the Civil War. |
| 1897 | Delaware adopted its present Constitution. |
| 1951 | The Delaware Memorial Bridge opened, connecting Delaware with New Jersey. |
| 1957 | The state began providing funds for needy students to attend the University of Delaware. |
| 1963 | The Delaware Turnpike John F. Kennedy Memorial Highway was opened, completing a nonstop highway between Boston and Washington, D.C. |
| 1971 | The Delaware Coastal Zone Act prohibited construction of industrial plants in coastal areas. |
| 1981 | The Delaware legislature passed the Financial Center Development Act, which made the state attractive for credit card operations. |
| 2000 | Ruth Ann Minner became the first woman elected governor of Delaware. She was reelected in 2004. |

