Eighteenth-century Britain was the world's leading exponent of the slave trade: profits soared and among the beneficiaries were the Church of England and London's Tate Gallery. Yet in the space of a few short years, beginning in 1788, a group of Abolitionists moved the cause of anti-slavery to the very centre of British political life, from the floor of Parliament to the homes of 300,000 people boycotting Caribbean sugar. At their head was Thomas Clarkson, a divinity student who travelled 35,000 miles on horseback documenting abuses, talking to supporters, and evading attempts on his life. With Granville Sharp and James Phillips he founded the Society for Effecting the Abolition of the Slave Trade, and gave platforms to freed slaves such as Olaudah Equiano, who had experienced the horrors in full. Clarkson's movement resembled nothing England had ever seen before: outside both Parliament and Church, it was the first major embodiment of the forces that today we call civil society, and Hochschild, drawing on the voluminous letters and journals of the characters involved, brings it compellingly to life.