Capitalism reached its zenith in the nineteenth and twentieth century’s. Following the upheavals and wars of the French Revolution and the Napoleonic period the nineteenth century was relatively peaceful although punctuated by revolutions in the first half of the century. The overthrow of the Ancien Regime by the French Revolution is a prime example of quantitative or additive long-term change suddenly transforming itself into qualitative change. It marked the last and greatest of the early modern bourgeois revolutions and the onset of modernity. Plantation slavery was a mechanism that allowed a process of ongoing primitive accumulation in the colonies to feed capitalist accumulation based on the exploitation of wage labour in England and Western Europe. The ideology of free labour inspired the anti-slavery movement in the United States. It also allowed a limited truce in the emerging class struggle between labour and capital.