The first abolition society in North America is established. The Society for the Relief of Free Negroes Unlawfully Held in Bondage is organized in Philadelphia by Benjamin Franklin and Benjamin Rush.

The Society for the Relief of Free Negroes Unlawfully Held in Bondage was the first American abolition society. It was founded April 14, 1775, in Philadelphia, Pennsylvania and held four meetings. Seventeen of the 24 men who attended initial meetings of the Society were Quakers, that is, members of the Religious Society of Friends, a branch of Christianity notable in the early history of Pennsylvania.

It was reorganized in 1784 as the Pennsylvania Society for Promoting the Abolition of Slavery and for the Relief of Free Negroes Unlawfully Held in Bondage, (better known as the Pennsylvania Abolition Society) and was incorporated in 1789.

At some point after 1785, Benjamin Franklin was elected as the organization's president. The society asked him to bring the matter of slavery to the Constitutional Convention of 1787. He petitioned the U.S Congress in 1790 to ban slavery.The Pennsylvania Abolition (or Abolitionist) Society, which had members and leaders of both races, became a model for anti-slavery organizations in other states during the antebellum years. Prominent African-American members included Robert Purvis, who was admitted in 1842 as the Society's first Black member. In 1984 when the Society was revived, a Pennsylvania State Historical Marker was placed on Philadelphia's Front Street below Chestnut Street, at the site of its original offices.The Pennsylvania Abolition Society still exists, dedicated to the cause of combating racism. The oldest abolitionist organization in the United States, since the late twentieth century, it has worked to improve issues of criminal justice and the over-representation of African Americans in prison, reduction in harsh sentencing laws, and improving economic and environmental justice.

In the United States, abolitionism, the movement that sought to end slavery in the country, was active from the late colonial era until the American Civil War, the end of which brought about the abolition of American slavery through the Thirteenth Amendment to the United States Constitution (ratified 1865).

The anti-slavery movement originated during the Age of Enlightenment, focused on ending the trans-Atlantic slave trade. In Colonial America, a few German Quakers issued the 1688 Germantown Quaker Petition Against Slavery, which marks the beginning of the American abolitionist movement. Before the Revolutionary War, evangelical colonists were the primary advocates for the opposition to slavery and the slave trade, doing so on humanitarian grounds. James Oglethorpe, the founder of the colony of Georgia, originally tried to prohibit slavery upon its founding, a decision that was eventually reversed.

During the Revolutionary era, all states abolished the international slave trade, but South Carolina reversed its decision. Acting as soon as the Constitution allowed, in 1807 Congress made the importation of slaves a crime. From the Revolutionary War to 1804, all Northern states abolished slavery either immediately or gradually. No Southern state did so. Immediate emancipation became a war goal for the Union in 1862 and was fully achieved in 1865.