Why did so few colonists in eighteenth-century New York, New Jersey, and Pennsylvania use slave labor?

The resulting Atlantic slave trade was primarily shaped by the desire for cheap labor as the colonies attempted to produce raw goods for European consumption.

Explanation:

European colonists in the Americas initially practiced systems of both bonded labor and indigenous slavery. However, for a variety of reasons, Africans replaced American Indians as the main population of enslaved people in the Americas. In some cases, such as on some of the Caribbean Islands, warfare and disease eliminated the indigenous populations completely. In other cases, such as in South Carolina, Virginia, and New England, the need for alliances with American Indian tribes, coupled with the availability of enslaved Africans at affordable prices, resulted in a shift away from American Indian slavery.

The resulting Atlantic slave trade was primarily shaped by the desire for cheap labor as the colonies attempted to produce raw goods for European consumption. Many American crops (including cotton, sugar, and rice) were not grown in Europe, and importing crops and goods from the New World often proved to be more profitable than producing them on the European mainland. However, a vast amount of labor was needed to create and sustain plantations that would be economically profitable. Western Africa (and later, Central Africa) became a prime source for Europeans to acquire enslaved peoples, to meet the desire for free labor in the American colonies, and to produce a steady supply of profitable cash crops.