The counties of Delaware are traditionally divided into "Hundreds", a division of English origin so-called because it was the unit of land sufficient to support one hundred men in the local militia. When Penn established the usage in the area that eventually came to be Delaware, the term was used to designate an area that contained one hundred families. Hundreds are used today only in the State of Delaware. At various times the unit was used in association with votng districts and for collecting taxes. Today the unit is used primarily in terms of property records. (See: The Hundreds of Delaware.)

The following map shows the distribution of modern hundreds. Some original hundreds have become extinct, either having been renamed, or subsumed within other hundreds. A list of Hundreds, extinct or extant, follows, based on Delaware Counties and Hundreds presented by the Delaware Genealogical Society, and derived from the work Delaware Genealogical Research Guide - 2nd edition (Doherty, 1997)