However, "Capitalism and Slavery" covers the economic history of sugar and slavery beyond just the Revolutionary and Napoleonic Wars, and discusses the decline of sugar plantations from 1823 until the Emancipation of the slaves in the 1830s. It also discusses the British government's use of the equalisation of the sugar duties Acts in the 1840s to sever their responsibilities to buy sugar from the British West Indians colonies, and to buy sugar on the open market from Cuba and Brazil, where it was cheaper. In support of the Williams thesis, David Ryden presented evidence to show that by the early nineteenth century there was an emerging crisis of profitability. Williams' arguments that the plantation system fuelled the Industrial Revolution are now established.