Long Island has had a long recorded history from the first European settlements in the 17th century to today. Greatly influenced by construction of railroads in the 19th century, it experienced growth in tourism as well as the development of towns and villages into some of the first modern suburbs in the United States.

Native American settlements

At the time of European contact, the Lenape people (named the Delaware by Europeans) inhabited the western end of the Island, and spoke the Munsee dialect of the Algonquian language family. Giovanni da Verrazzano was the first European to record an encounter with these people when he entered what is now New York Bay in 1524.

The eastern portion of the island was inhabited by speakers of the Mohegan-Montauk-Narragansett language group of the same language family, representing their ties to the Aboriginal peoples inhabiting what is now Connecticut and Rhode Island. The area was central to the production of Wampum, providing the resources necessary for its creation.

Decades after the decline in population of Native American on Long Island, amateur anthropologist Silas Wood published a book claiming that there had been several homogenous "tribes" traditional to Long Island; they erroneously became collectively known as the Metoac, a word that has no known Native American origin and means nothing in any Indigenous language on Long Island. Modern scientific scholarship has shown that there were two linguistic groups representing two cultural identities on the island, as noted above, not "13 tribes" as asserted by Wood. The Montaukett, Unkechaug, and Shinnecock nations, three Native American groups with ties to aboriginal inhabitants, still live on the island.

A Native American name for Long Island is Paumanok, meaning "The Island that Pays Tribute". More powerful tribes in the surrounding areas forced the relatively peaceful Long Islanders to give tributes and payment to avoid attacks.

Colony

Dutch and English Settlements

The western portion of Long Island was settled by the Dutch, who named it 't Lange Eylandt, which translates to the Long Island in old-Dutch. They also had early settlements in the 17th century on what are now Manhattan and Staten Island.

On April 22, 1636, Charles I of England ordered that the Plymouth Colony, which had laid claim to the island but had not settled it, give the island to William Alexander. Alexander through his agent James Farret (who personally received Shelter Island and Robins Island) in turn sold most of the eastern island to the New Haven and Connecticut colonies.

English settlers first arrived at Southold in eastern Long Island in 1636/37 and were involved in the distillation of turpentine resins. Among those who first settled in Southold were Matthew Sunderland, William Salmon, Thomas Reeve, Thomas Terrill, Thomas Benedict, and Henry Whitney, with Sunderland, Salmon, Whitney, and Benedict taking equal ownership of land tracts Sunderland had received from Farret. Lion Gardiner was among the first English settlers as he settled on Gardiners Island in 1637.

Farret arrived in New Amsterdam in 1637 to present his claim of English sovereignty and was arrested and sent to prison in Holland where he escaped. English attempted to settle at Cow Bay at what today is Port Washington in May 1640 but were arrested and released after saying they were mistaken about the title.

English settlements on the east end began in earnest shortly thereafter.

Puritans from New Haven, Connecticut, arrived in present-day Southold on October 21, 1640. Under the leadership of the Reverend John Youngs (1598–1672), with Peter Hallock, the families of Barnabas Horton ( 1600–1680), John Budd, John Conklin (1600–1684), William Wells, John Tuthill, Thomas Mapes, Richard Terry, Matthias Corwin, Robert Akerly, Zachariah Corey and Isaac Arnold planted the first English and first white settlement in eastern Long Island. They purchased the land in the summer of 1640 from an Indian tribe named the Corchaugs. The Corchaug name of what became Southold was Yenniock. Southampton was founded when settlers from Lynn, Massachusetts established residence on lands obtained from local Shinnecock Indian Nation also in 1640. The first settlers included eight men, one woman, and a boy who came ashore at Conscience Point. Dutch complaints did not matter. Officials of the Colony of New Netherland did not make immediate efforts to expel the English from such a remote place.

Southold remained under the jurisdiction of New Haven until 1662, and of Connecticut until 1674. When the English handed over the colony of New York to the Dutch in 1673, the eastern towns, including Southold, Easthampton and Southampton, refused to submit. The Dutch attempted to force the matter by arms. The English colonists repelled them with assistance from Connecticut settlers.

When New York became English again in 1674, these eastern towns, whose people were Yankee by background, preferred to stay part of Connecticut. Although Connecticut agreed, the government of the Duke of York forced the matter. Governor Sir Edmund Andros threatened to eliminate the settlers' rights to land if they did not yield, which they did by 1676. This was chiefly the result of the Duke of York's grudge against Connecticut, as New Haven had hidden three of the judges who sentenced the Duke's father King Charles I to death in 1649.

Long Island contained three of the original twelve counties of the English Province of New York organized in 1683: Kings, Queens, and Suffolk. At that time, Queens County included all of present-day Nassau County and a small portion of western Suffolk County.

Residents in Long Island towns conducted several witch hunts, including one involving the daughter of Lion Gardiner in East Hampton. Early colonial figures on the island include Wyandanch, William "Tangier" Smith, Captain William Kidd, Lion Gardiner, and John Underhill.

Revolutionary War

The Battle of Long Island, the largest Revolutionary War battle, ranged across Kings County, now the Borough of Brooklyn in New York City. Apart from espionage and raids across Long Island Sound, there was limited military action in Queens and Suffolk County. Throughout most of the war, Long Island was controlled by the King's forces. As was customary, they billeted Hessian and regular troops with local households, who had to provide bedding and food for soldiers. In Oyster Bay, Major John André was visiting the headquarters of Lt. Col. James Simcoe at Raynham Hall, the family home of Robert Townsend, one of George Washington's Culper Ring spies. Townsend family legend holds that Robert's sister Sally overheard André and Simcoe discussing Benedict Arnold's treasonous plan to turn West Point over to the King's forces.

Colonists conducted numerous raids on Long Island during the war, usually by whaleboats from Connecticut. The most famous raid was the Sag Harbor or Meigs Raid in 1777. Possibly the last battle of the American Revolution was the "Boat Fight" of December 1782.

Nineteenth century

In the 19th century, Long Island was still mainly rural and agricultural. Suburbanization started modestly on Long Island when reliable steam ferry service allowed prosperous Wall Streeters to get to new Brooklyn Heights homes in time for dinner. Rural traffic was served by the new Brooklyn and Jamaica Plank road through Jamaica Pass, among others. After the American Civil War, streetcar suburbs sprawled out onto the outwash plain of central and southern Kings County. Trolleys also brought workers from other parts of western Queens to Long Island City jobs.

The Long Island Rail Road was begun as a combined ferry-rail route to Boston via Greenport. The predecessor to the Long Island Rail Road began service in 1836 from the ferry terminal (to Manhattan) through Brooklyn to Jamaica in Queens, and completed the line to the east end of Long Island in 1844. Other rail lines to Coney Island, the Rockaways and Long Beach serviced the beach resort towns. The growing and merging railroads opened up more than 50 stations in (present-day) Nassau County and over 40 in Suffolk Country, laying the foundation for the future suburbanization of the island.

From 1830 until 1930, population roughly doubled every twenty years, and several cities were incorporated, such as the City of Brooklyn in Kings County, and Long Island City in Queens.

By the late 19th century, Long Island had become a summer refuge for residents of New York City. The Landing, in Glen Cove, is named for the spot where 19th-century steamship lines would disembark summer visitors, not far from where J. P. Morgan had his summer mansion. Long Island was the home of a branch of the prominent Roosevelt family, including author Robert Roosevelt, and his more famous nephew, President Theodore Roosevelt, who built a summer home at Sagamore Hill on the North Shore of Nassau County – on the outskirts of Oyster Bay. Roosevelt Field was named after Quentin Roosevelt, Theodore's son. Gold Coast Mansions on the North Shore of Long Island were also the homes of the wealthy Vanderbilt family and late-19th-century financiers and industrialists, such as John Paul Getty, Charles Pratt and others.

Until the 1883 completion of the Brooklyn Bridge, the only connection between Long Island and the rest of the United States was by boat. Other bridges and tunnels followed, and a suburban character spread as population increased.

On January 1, 1898, Kings County and portions of Queens were consolidated into The City of Greater New York, abolishing all cities and towns within them. The easternmost 280 square miles (725 km2) of Queens County, which were not part of the consolidation plan, formed a separate county in 1899. "Nassau", one of several names by which the island was once known, was revived to represent the newly established county.

Slavery on Long Island Black people have been an integral part of Long Island history, most arriving first as slaves before the Revolution and working both at domestic and rural trades. New York and Long Island kept slavery until laws for its gradual abolition were passed in 1799. The last slaves were freed by 1827. Most freedmen settled near where they had been living.

With the small family farms and industrial economy within the North, the need for slavery was much less than in the Southern United States. Slavery tended to be more common in rural areas of the Northeast, like Long Island, rather than in the cities. Slavery took a different form in the Northern states than on Southern plantations. While slaves were still treated as property by law, and included as bequests in wills, they were fewer in number. On Long Island, it was typical for farmers to own five or six slaves per household. They lived closely within the family, sometimes within the same quarters.

After the Civil War, the issue of race increased on Long Island, as well as surrounding areas in New York. Fears of freed blacks taking the jobs of working-class whites created tensions in addition to tensions with immigrant communities seeking work. As time progressed, African Americans within the local Tri-State area began to work in industrialized cities such as New York City and Philadelphia.

Growth in the 20th century