In eighteenth-century England, many good Christian people ignored the inhumane treatment of slaves. Slavery was far away. It did not involve them. They were too busy.
Then in 1781, an overcrowded slave ship, the Zong, veered off course, and began to run low on water. The crew reviewed the insurance policy, which stated that no reimbursement would be dispensed if slaves died of natural causes on the ship or on shore, but a claim could be made if cargo was thrown overboard to save the other cargo. Since slaves were considered cargo, the crew decided to jettison 133 slaves overboard, letting them drown in the ocean below. In a sad twist, the ship arrived at port with 430 gallons of water to spare.
The owners of the ship then decided to make an insurance claim against the lost cargo, which were the murdered slaves. A lengthy legal case arose from the claim, and soon abolitionists caught news of the incident. They began to use the story in their literature in order to stir the English population out of their apathy.
How could you sit there and do nothing when innocent people were being killed? How could Christians not care that slaves were thrown overboard for money? The Zong massacre opened the veil covering the horridness of the slave trade, and allowed people to get a glimpse of its inhumanity.