The first known inhabitants of Delaware were the Lenni Lenape and the Nanticoke. Their descendants today comprise the federal Delaware Tribe of Indians and Delaware Nation, both now based in Oklahoma, and the state-recognized Nanticoke Indian Association and the Lenape Indian Tribe of Delaware and the Nanticoke Lenni-Lenape of New Jersey, as well as the Stockbridge Munsee of Wisconsin, and the Moravian Delaware Nation of Ontario Canada.

Beginning in the 1630s, colonial governments were established, for varying lengths of time, by the Dutch, the Swedes, the Dutch again, and the English. In 1682, the "Three Lower Counties" of what is now Delaware became part of Pennsylvania until the Revolutionary War.

Delaware became a state in 1776. In 1787, it became the first state, and the first of the 13 original colonies, to ratify the U.S. Constitution.

This guide offers a selection of resources and strategies for Delaware local history and genealogy research. These include the print and digital collections of the Library of Congress, as well as external repositories and web sites key to finding forebears in the "First State."