The first New York State constitution, written in 1777, based itself on the Declaration of Independence. Did "all men are created equal" mean that slavery was illegal? Conversely, could the new government take away a slaveholder's legal property without compensation?

Slavery was a part of every American colony until outlawed in the first Vermont constitution of 1777. Pennsylvania gradually abolished slavery, beginning three years later. Court decisions freed all Massachusetts slaves by 1783. In New York, slavery remained economically important. Emancipation came grudgingly, and not completely until 1827.
Slavery continued in the city after 1783, but now free blacks were present and their numbers were growing. New laws made it easier for owners to manumit their slaves. Political leaders in the New York Manumission Society (founded in 1785) argued for abolition. Yet, unlike Pennsylvania, Connecticut, and Rhode Island, New York delayed passing any emancipation act. Indeed, in 1788, it enacted a new slave code legitimizing most colonial restrictions. But in 1799, the state finally enacted its own gradual emancipation law, promising freedom to all newborn blacks over the coming decades.
Leading the Struggle Against Slavery in New York State
The New York Manumission Society