The Convention to frame the Constitution met in Philadelphia (1787). George Washington was its President; it was composed of the leading statesmen of the new nation, sitting in a delegate capacity, but in voting on measures the rule of the then Congress was observed, which was to vote by States. The majority of the thirteen States were then slave States, and all, save Massachusetts, still held slaves; and all the coast States indulged in the African slave trade. Massachusetts provided for the abolition of slavery in 1780 by constitutional provision declaring that: "All men are born _free and equal_, and have certain natural, essential, and unalienable rights," etc., by which declaration its highest judicial tribunal struck the shackles at once from every slave in the Commonwealth. Connecticut provided in 1784 for freeing her slaves. New Hampshire did not prohibit slavery by express law, but all persons born after her Constitution of 1776 were free; and slave importation was thereafter prohibited. Pennsylvania, in 1780, by law provided for the gradual emancipation of slaves within her territory. To her German population and the Society of Friends the credit is mainly due for this act of justice. This Society had theretofore (1774) disowned, in its "yearly Meeting," all its members who trafficked in slaves; and later (1776) it resolved: "That the owners of slaves, who refused to execute proper instruments for giving them their freedom, were to be disowned likewise." New York adopted gradual emancipation in 1799, but final emancipation did not come until 1827. Rhode Island, in the first year of the First Continental Congress (1774), enacted: "That for the future no negro or mulatto slave shall be brought into the colony . . . and that all previously enslaved persons on becoming residents of Rhode Island should obtain their freedom." New Jersey in 1778, through Governor Livingstone, made an attempt at emancipation which failed; it was not until 1804 that she prohibited slavery in what proved a qualified way, and it seems she held slaves at each census, including that of 1860, and possibly in some form human slavery was abolished there by the Thirteenth Amendment to the Constitution. The census of 1790 showed slaves in all the original States save Massachusetts alone; Vermont was admitted into the Union in 1790; her Constitution prohibited slavery, but she returned at that census seventeen slaves. The first census under the Constitution, however, showed, in the Northern States, 40,370 slaves, and in the Southern States, 657,572; there being in Virginia alone 293,427, nearly one half of all. The Convention closed its work September 17, 1787, and on the same date George Washington, its President, by letter submitted the "Constitution to the consideration of the United States in Congress assembled," saying: