One area of increasing concern, the growing opposition to slavery, brought tensions and controversy among Friends as they wrestled with their varied attitudes to the problem. In 1688, a letter opposing slavery was brought before the Germantown, Pennsylvania, Monthly Meeting. Though action was deferred, it appears that this was the first protest against slavery raised by any religious group in America. In 1711, the Philadelphia Yearly Meeting influenced the then Quaker-controlled Pennsylvania Assembly to forbid the importation of slaves, but the Crown failed to approve it. John Woolman (1720–1772) was one of the strongest witnesses against the traffic and holding of slaves and played a large role in persuading Friends to free their slaves.

William Burling of Flushing expressed the first recorded concern on the subject of slavery in New York Yearly Meeting in 1718. No action was taken at that time, but in 1767 the Oblong Monthly Meeting reopened the concern with the Purchase Quarterly Meeting. The yearly meeting considered this issue in 1776, and in 1777 directed New York Friends to manumit their slaves. By 1790, it appears that no Friends in the United States owned slaves, and many were actively working for abolition. Among these were several women, notably Lucretia Coffin Mott (1793–1880) and Susan B. Anthony (1820–1906), who, even before the end of the Civil War, worked with other women for peace, temperance, and rights for women.

After 1750, the French and Indian Wars in America resulted in Friends concluding that they must withdraw from active involvement in government in order to maintain the peace testimony. In its militia law of 1755, New York’s provincial government exempted Quakers from service on payment of a fee. This arrangement was unacceptable to the Quakers. However, in complying with the authorities’ demand for lists of those Friends eligible for the exemption, the monthly meetings provided the first semblance of membership lists of the Society in New York. Later, the War for Independence further separated Quakers from their neighbors as most Friends attempted to maintain a neutral position, neither Patriot nor Loyalist.

As the abolition movement came increasingly to accept violent means to root out the evil of slavery, Friends were under great stress trying to maintain their testimony against war. During the Civil War, meetings disowned a number of Friends for violating the testimony against war by serving in the armed forces even though they were upholding that against slavery.

Although many Friends were active in social reform movements, many others, influenced by the Quietism spreading through other sects, gradually dissociated themselves from worldly issues and lessened active witness in and to the world. They began to emphasize the care of the individual soul and the meeting. Friends formed their own close communities, holding to their pacifist witness and the customs that set them off as a “peculiar people,” and sought the guidance of God in their inner lives. They stressed the belief in absolute human helplessness before God and our tendency toward error and evil when we act in our own wisdom. Friends in worship waited in silence for the inner movement of God’s spirit to reprove, guide, and strengthen them, and they came to value their meetings more for the quality of the silence than for the quality of the ministry. They considered each individual an instrument upon whom God plays, an instrument whose usefulness to God would become apparent only through self-negation and quiet waiting.

Friends tried to witness for God’s peaceable kingdom within their communities, and each yearly meeting came to adopt a book of discipline that provided the basis for sound Quaker business and social structure. The advices and queries contained within these disciplines gave guidance for corporate and personal conduct without establishing a creed. But as Friends became more insular and self-contained, they paid much attention to prescribing and enforcing rules of behavior. Such rules as forbidding marriage to nonmembers resulted in the disownment of valuable members and the alienation of many others.

A markedly greater number of women became active in the ministry during this time. Meetings formally recognized the call to ministry in many men and women; these ministers were nurtured by the increased emphasis on care for the individual soul and often felt inward calls to visit other meetings. Friends, even in areas very far from other settlements, kept in touch with each other by means of these traveling ministers. The travelers themselves helped gather into meetings with Friends persons who felt Christ’s light. The practice of appointing younger Friends as companions to traveling ministers afforded a kind of apprenticeship in the ministry. Several generations found themselves stronger Friends because of these visits in their youth.

Friends had already been concerned and involved in education. They extended this concern to those whom society excluded from schooling—females, blacks, and Indians—despite opposition from the non-Quaker community and from the Indians themselves. As early as 1779, the New York Yearly Meeting recommended that the quarterly and monthly meetings establish schools for Friends’ children. In 1791, several were in operation, and in that same year the yearly meeting called on preparative meetings to establish schools. Friends Seminary in New York City opened in 1786. The Nine Partners Boarding School, founded in 1796 as the yearly meeting school, preceded the Friends Academy at Union Springs, opened in 1858, which in 1920 moved to Poughkeepsie as the present Oakwood Friends School.

In the nineteenth and twentieth centuries, New York Yearly Meeting Friends helped found several other schools: the New York City public schools in the early 1800s, Brooklyn Friends School (1867), Friends Academy in Locust Valley (1877), the Westbury Friends School (1957), Friends World College (1965), and the Mary McDowell Center (1983), in Brooklyn. Some of them continue under the care of Friends.