First settled by the English in 1664, the township was originally called Monomoit based on the indigenous population's term for the region.

Native American tribes who lived in the area before European colonization included the Nauset, specifically the Manomoy or Monomoy people.

Explorer Samuel de Champlain landed there in October 1606 at a place he christened "Port Fortuné", where conflict arose with the Nauset.

[1] Neither name stuck, and the location was not permanently occupied by Europeans until English settlers reached Monomoit in 1664.

Today, the keeper's house is home to a Coast Guard station which patrols the waters of the Atlantic and Nantucket Sound from Wellfleet to West Yarmouth.

The first reforesting project in America took place on Great Hill in 1821 when Selectmen had pine trees and beach grass planted to prevent erosion and to keep sand from blowing over the village.

[3] Although urban sprawl has invaded the Cape, the town of Chatham still boasts a quaint and walkable Main Street, home to numerous family-owned and -operated shops, restaurants, and businesses.

[7] In summer, Chatham grows to a population of an estimated 30,000,[citation needed] making facilities overcrowded, and there is limited parking in the Main Street Business District.

Chatham is bordered by Harwich to the west, Pleasant Bay and Orleans to the north, the Atlantic Ocean to the east, and Nantucket Sound to the south.

The town includes two narrow strips of land that serve as a barrier between the Atlantic and the mainland; the northern of these is the southern part of the Cape Cod National Seashore.

Erosion has changed the region over the years—for example, an island named Slut's Bush once existed until it vanished underwater by the mid-19th century.

The area surrounding Chatham is home to diverse flora and fauna, including many species that rely on the wetlands for survival.

The salt marshes and lakes that exist in the region due to glacial action from the last ice age are essential habitats for many species, such as ospreys (Pandion haliaetus) and striped bass (Morone saxatilis).

These wetlands not only promote biodiversity but also act as natural filters, retaining particulates and purifying the water that flows into nearby estuaries and bays.

[12] However, Chatham's beaches have experienced significant vegetation loss in recent decades due to both natural and human causes.

[13] Despite this, the beaches remain important nesting sites for various species of sea turtles and shorebirds, such as the Piping Plover (Charadrius melodus), while the waters off the coast are rich in marine life, including seals (Halichoerus grypus), whales, and sharks, such as the great white shark (Carcharodon carcharias).

During the summer months (generally Memorial Day through Labor Day), the town's population triples to approximately 20,000, not counting the additional transient tourist population hosted by the town's many hotels, inns, motels, and bed and breakfasts.

[20] The Chatham Police Department is the primary law enforcement agency that services the town.

The Police station was recently constructed in 2012 and is located on George Ryder Road, across the street from the Chatham Municipal Airport.

Troopers from the Massachusetts State Police Troop D Yarmouth barracks provide secondary law enforcement services to the town.

On the national level, Chatham is a part of Massachusetts's 9th congressional district and is represented by William R. Keating.

In March 2013, construction began in Harwich on a new high school to serve the region, expected to open in 2014.

The team plays at Veteran's Field and has featured dozens of players who went on to careers in Major League Baseball, such as Thurman Munson, Jeff Bagwell, and Kris Bryant.