The northern isthmus of the peninsula is transected by the Chesapeake and Delaware Canal. Several bridges cross the canal, and the Chesapeake Bay Bridge and the Chesapeake Bay Bridge-Tunnel join the peninsula to mainland Maryland and Virginia, respectively. Another point of access is Lewes, Delaware, reachable by ferry from Cape May, New Jersey.
Dover, Delaware's capital city, is the peninsula's largest city (by population), but the main commercial area is Salisbury, Maryland, near its center. Including all offshore islands (the largest of which is Kent Island in Maryland), the total land area south of the Chesapeake and Delaware Canal is 14,127.044 km² (5,454.482 sq mi). At the 2000 census the total population residing in this area was 681,030 inhabitants. Its average population density was therefore 48.2 persons/km² (124.86 persons/sq mi).
Roughly south of Wilmington, Delaware, is the fall line, a geographic borderland where the Piedmont region transitions into the coastal plain, a flat, sandy area with very few or no hills.
All three counties in Delaware – New Castle, Kent, and Sussex – are located on the peninsula (though upper New Castle county only in part). Of the 23 counties in Maryland, nine are on the Eastern Shore: Kent, Queen Anne's, Talbot, Caroline, Dorchester, Wicomico, Somerset, and Worcester, as well as a portion of Cecil County. Two Virginia counties are on the peninsula: Accomack and Northampton.
The following is a list of some of the notable cities and towns in the peninsular region.
At various times in its history, residents of the peninsula have proposed that its Maryland and Virginia portions secede from their respective states, merging with Delaware to create a new state named Delmarva.
The land that is currently Delaware was colonized by the Dutch in 1631 as Zwaanendael. That colony lasted one year before a dispute with local Indians led to its destruction. Some years later, Sweden colonized the northern part of the state, over Holland's objections. Eventually, the Dutch, who had maintained that their claim to Delaware arose from the colony of 1631, recaptured Delaware and incorporated the colony into the Colony of New Netherland. However, shortly thereafter Delaware came under British control in 1664. The land was transferred from the Duke of York to William Penn in 1682 and was governed with Pennsylvania. The exact border was determined by the Chancery Court in 1735. In 1776, the counties of Kent, New Castle, and Sussex declared their independence from Pennsylvania and entered the United States as the State of Delaware.
In the 1632 Charter of Maryland, King Charles I of England granted "all that Part of the Peninsula, or Chersonese, lying in the Parts of America, between the Ocean on the East and the Bay of Chesapeake on the West, divided from the Residue thereof by a Right Line drawn from the Promontory, or Head-Land, called Watkin's Point, situate upon the Bay aforesaid, near the river Wigloo, on the West, unto the main Ocean on the East; and between that Boundary on the South, unto that Part of the Bay of Delaware on the North, which lieth under the Fortieth Degree of North Latitude from the Equinoctial, where New England is terminated" to Cæcilius Calvert, 2nd Baron Baltimore as the colony of Maryland. This would have included all of present-day Delaware; however, a clause in the charter granted only that part of the peninsula that had not already been colonized by Europeans by 1632. Over a century later, it was decided in the case of Penn v. Lord Baltimore that because the Dutch had colonized Zwaanendael in 1631, that portion of Maryland's charter granting Delaware to Maryland was void.
The Eastern Shore is also known for its poultry farms, the most well-known of which is Perdue Farms, founded in Salisbury, Maryland. The Delaware is a rare breed of chicken created on the peninsula.