Das Kapital (1867) is an economic treatise by Karl Marx. The book is an analysis of capitalism. Marx bases his work on that of the classical economists like Adam Smith, David Ricardo, and even Benjamin Franklin. The central injustice of capitalism, according to Marx, was that employers made their profits by paying labourers less than the true value of their labour.
Marx died before he could finish the second and third volumes, but a version of the entire work was published posthumously, edited by his friend Friedrich Engels. The work included a three-volume appendix, The Theory of Surplus Value. The first English edition of Das Kapital, Capital: A Critique of Political Economy, also edited by Engels, was published in 1887.