Which group established the first formal campaigns against slavery?

The Quakers, formally known as the Religious Society of Friends, were pioneers in advocating for social justice, and their stance against slavery is a significant part of their history. Originating in 17th-century England during a time of religious and social upheaval, the Quakers developed a belief in the inherent equality of all people, regardless of race, gender, or social status. This conviction stemmed from their core belief that everyone possesses an "inner light," a divine spark that makes each individual worthy of respect and dignity. By the late 1600s, prominent Quakers like George Fox and William Penn began speaking out against the enslavement of Africans, viewing it as a profound violation of human rights and a contradiction of Christian principles. While other groups may have had concerns about the slave trade, the Quakers were the first to formally organize campaigns and actively lobby for its abolition, making them the correct answer. The Cavaliers and Roundheads were factions in the English Civil War, while the Jacobites sought to restore the Stuart monarchy; none of these groups are primarily known for their anti-slavery efforts.