 
The trafficking of enslaved Africans to what became New York began as part of the Dutch slave trade. The Dutch West India Company trafficked eleven enslaved Africans to New Amsterdam in 1626, with the first slave auction held in New Amsterdam in 1655. With the second-highest proportion of any city in the colonies (after Charleston, South Carolina), more than 42% of New York City households enslaved African people by 1703, often as domestic servants and laborers. Others worked as artisans or in shipping and various trades in the city. Enslaved Africans were also used in farming on Long Island and in the Hudson Valley, as well as the Mohawk Valley region.
During the American Revolutionary War, the British troops occupied New York City in 1776. The Philipsburg Proclamation promised freedom to enslaved persons who left rebel masters, and thousands moved to the city for refuge with the British. By 1780, 10,000 Black people lived in New York. Many had escaped from their enslavers who lived in both northern and southern colonies. After the war, the British evacuated about 3,000 enslaved people from New York, taking most of them to resettle as free people in Nova Scotia, where they are known as Black Loyalists.
Of the Northern states, New York was next to last in abolishing slavery. (In New Jersey, mandatory, unpaid "apprenticeships" did not end until the Thirteenth Amendment ended slavery, in 1865.)
After the American Revolution, the New York Manumission Society was founded in 1785 to work for the abolition of slavery and to aid free Black people. The state passed a 1799 law for gradual abolition, a law which freed no living slave. After that date, children born to enslaved mothers were required to work for the mother's enslaver as indentured servants until age 28 (men) and 25 (women). The last enslaved persons were freed of this obligation on July 4, 1827 (28 years after 1799). African Americans celebrated with a parade.
Upstate New York, in contrast with New York City, was an anti-slavery leader. The first meeting of the New York State Anti-Slavery Society opened in Utica, although local hostility caused the meeting to be moved to the home of Gerrit Smith, in nearby Peterboro. The Oneida Institute, near Utica, briefly the center of American abolitionism, accepted both Black and white male enrollees on an equal basis, as did for women the Young Ladies' Domestic Seminary in nearby Clinton. New-York Central College, near Cortland, was an abolitionist institution of higher learning founded by Cyrus Pitt Grosvenor, that accepted all students without prejudice: male and female, white, Black, and Native American, the first college in the United States to do so from the day its doors opened. It was also the first college to have Black professors teaching white students. However, when a Black male faculty member, William G. Allen, married a white student, they had to flee the country for England, never to return.
Dutch rule.
Initial group of slaves.
In 1613, Juan (Jan) Rodriguez from Santo Domingo became the first non-indigenous person to settle in what was then known as New Amsterdam. Of Portuguese and West African descent, he was a free man.
Systematic slavery began in 1626, when eleven captive Africans arrived on a Dutch West India Company ship in the New Amsterdam harbor. Historian Ira Berlin called them Atlantic Creoles who had European and African ancestry and spoke many languages. In some cases, they attained their European heritage in Africa when European traders conceived children with African women. Some were Africans who were crew members on ships and some came from ports of the Americas. Their first names—like Paul, Simon, and John—indicated if they had European heritage. Their last names indicated where they came from, like Portuguese, d'Congo, or d'Angola. People from the Congo or Angola were known for their mechanical skills and docile manners. Six slaves had names that indicated a connection with New Amsterdam, such as Manuel Gerritsen, which he likely received after their arrival in New Amsterdam and to differentiate from repeated first names. Men were laborers who worked the fields, built forts and roads, and performed other forms of labor. According to the principle of "partus sequitur ventrem" adopted from southern colonies, children born to enslaved women were considered born into slavery, regardless of the ethnicity or status of the father.In February 1644, the eleven slaves petitioned Willem Kieft, the director general for the colony, for their freedom. This was a time when there were skirmishes with Native American people and the Dutch wanted blacks to help protect their settlements and did not want the slaves to join the Native Americans. These eleven slaves were granted partial freedom, where they could buy land and a home and earn a wage from their master, and later full freedom. Their children remained in slavery. By 1664, the original eleven slaves, as well as other slaves who had attained half-freedom, for a total of at least 30 black landowners, lived on Manhattan near the Fresh Water Pond.
Slave trade.
For more than two decades after the first shipment, the Dutch West India Company was dominant in the importation of slaves from the coasts of Africa. A number of slaves were imported directly from the company's stations in Angola to New Netherland.
Due to a lack of workers in the colony, it relied upon on African slaves, who were described by the Dutch as "proud and treacherous", a stereotype for African-born slaves. The Dutch West India Company allowed New Netherlanders to trade slaves from Angola for "seasoned" African slaves from the Dutch West Indies, particularly Curaçao, who sold for more than other slaves. They also bought slaves that came from privateers of Spanish slave ships. For instance, "La Garce" a French privateer, arrived in New Amsterdam in 1642 with Spanish Negroes that were captured from a Spanish ship. Although they claimed to be free, and not African, the Dutch sold them as slaves due to their skin color.
Unlike slaves from other colonies, slaves in New Amsterdam could sue another person whether white or black. Early instances included suits filed for lost wages and damages when a slave's pig was injured by a white man's dog. Slaves could also be sued.
Partial and full freedom.
By 1644, some slaves had earned partial freedom, or half-freedom, in New Amsterdam and were able to earn wages. Under Roman-Dutch law they had other rights in the commercial economy, and intermarriage with working-class whites was frequent. Land grant records show that Land of the Blacks was located just north of New Amsterdam. As the English began to seize New Amsterdam in 1664, the Dutch freed about 40 men and women who had been granted half-slave status, to ensure that the English would not keep them enslaved. The new freemen had their original land grants finalized and all grants were officially marked as owned by the new freemen.
English rule.
In 1664, the English took over New Amsterdam and the colony. They continued to import slaves to support the work needed. Enslaved Africans performed a wide variety of skilled and unskilled jobs, mostly in the burgeoning port city and surrounding agricultural areas. In 1703, more than 42% of New York City's households held slaves, a percentage higher than in the cities of Boston and Philadelphia, and second only to Charleston in the South.
In 1708, the New York Colonial Assembly passed a law entitled "Act for Preventing the Conspiracy of Slaves" which prescribed a death sentence for any slave who murdered or attempted to murder his or her master. This law, one of the first of its kind in Colonial America, was in part a reaction to the murder of William Hallet III and his family in Newtown (Queens).
In 1711, a formal slave market was established at the end of Wall Street on the East River, and it operated until 1762.
An act of the New York General Assembly, passed in 1730, the last of a series of New York slave codes, provided that:
Forasmuch as the number of slaves in the cities of New York and Albany, as also within the several counties, towns and manors within this colony, doth daily increase, and that they have oftentimes been guilty of confederating together in running away, and of other ill and dangerous practices, be it therefore unlawful for above three slaves to meet together at any time, nor at any other place, than when it shall happen they meet in some servile employment for their masters' or mistresses' profit, and by their masters' or mistresses' consent, upon penalty of being whipped upon the naked back, at the discretion of any one justice of the peace, not exceeding forty lashes for each offense.
Manors and towns could appoint a common whipper at no more than three shillings per person. Blacks were given the lowest status jobs, the ones the Dutch did not want to perform, like meting out corporal punishment and executions.
As in other slaveholding societies, the city was swept by periodic fears of slave revolt. Incidents were misinterpreted under such conditions. In what was called the New York Conspiracy of 1741, city officials believed a revolt had started. Over weeks, they arrested more than 150 slaves and 20 white men, trying and executing several, in the belief they had planned a revolt. Historian Jill Lepore believes whites unjustly accused and executed many blacks in this event.
In 1753, the Assembly provided there should be paid "for every negro, mulatto or other slave, of four years old and upwards, imported directly from Africa, five ounces of Sevil[le] Pillar or Mexico plate [silver], or forty shillings in bills of credit made current in this colony."
American Revolution.
African Americans fought on both sides in the American Revolution. Many slaves chose to fight for the British, as they were promised freedom by General Guy Carleton in exchange for their service. After the British occupied New York City in 1776, slaves escaped to their lines for freedom. The black population in New York grew to 10,000 by 1780, and the city became a center of free blacks in North America. The fugitives included Deborah Squash and her husband Harvey, slaves of George Washington, who escaped from his plantation in Virginia and reached freedom in New York.
In 1781, the state of New York offered slaveholders a financial incentive to assign their slaves to the military, with the promise of freedom at war's end for the slaves. In 1783, black men made up one-quarter of the rebel militia in White Plains, who were to march to Yorktown, Virginia, for the last engagements.
By the Treaty of Paris (1783), the United States required that all American property, including slaves, be left in place, but General Guy Carleton followed through on his commitment to the freedmen. When the British evacuated from New York, they transported 3,000 Black Loyalists on ships to Nova Scotia (now Maritime Canada), as recorded in the "Book of Negroes" at the National Archives of Great Britain and the "Black Loyalists Directory" at the National Archives at Washington. With British support, in 1792 a large group of these Black Britons left Nova Scotia to create an independent colony in Sierra Leone.
Gradual abolition.
In 1781, the state legislature voted to free those slaves who had fought for three years with the rebels or were regularly discharged during the Revolution. The New York Manumission Society was founded in 1785, and worked to prohibit the international slave trade and to achieve abolition. It established the African Free School in New York City, the first formal educational institution for blacks in North America. It served both free and slave children. The school expanded to seven locations and produced some of its students advanced to higher education and careers. These included James McCune Smith, who gained his medical degree with honors at the University of Glasgow after being denied admittance to two New York colleges. He returned to practice in New York and also published numerous articles in medical and other journals.
In 1785, Aaron Burr introduced a bill in the state legislature for immediate emancipation that was defeated 33–13 . A more limited bill was soon introduced, providing for gradual emancipation, but restricting voting, prohibiting intermarriage and black testimony against whites. It was also defeated, 27–17. 
By 1790, one in three blacks in New York state were free. Especially in areas of concentrated population, such as New York City, they organized