Swedish colonists establish the first settlement in Delaware, naming it New Sweden.

William Penn receives the area that is now the state of Delaware, and adds it to his colony of Pennsylvania.

Delaware Separation Day – Delaware votes to suspend government under the British Crown and separate officially from Pennsylvania.

Delaware becomes the first state to ratify the United States Constitution.

Pennsylvania becomes the second state to ratify the United States Constitution five days after Delaware became the first.

American Civil War: Delaware votes not to secede from the United States.

In the United States, Delaware voters reject the Thirteenth Amendment to the U.S. Constitution, and vote to continue the practice of slavery. (Delaware finally ratifies the amendment on February 12, 1901.)

General Motors acquires the Chevrolet Motor Company of Delaware.