Karl Marx released the first volume of his monumental work 'Das Kapital' (Capital) on May 1, 1867, after more than a decade of painstaking research in the British Museum's reading rooms. The book laid out his theory of surplus value and exploitation of labor under capitalism, building on ideas he had sketched in the earlier 'Communist Manifesto.' Though it sold modestly during Marx's lifetime, it later became one of the most influential and contested texts in modern political history.
Marx had labored over the manuscript for years, often in dire poverty, relying on financial support from his friend and collaborator Friedrich Engels while he pored over British factory inspection reports, parliamentary records, and economic treatises inside the British Museum's domed reading room in London.
The book's central argument, that capitalists extract 'surplus value' from workers by paying them less than the value their labor creates, provided an intellectual framework that would later underpin revolutionary movements from Russia to China to Cuba. Marx intended it as a rigorous scientific critique rather than a manifesto, dense with statistics, historical analysis, and philosophical argument drawn from Hegel and classical economists like Ricardo and Smith.
During his lifetime the book found only a modest readership, and Marx never completed the subsequent volumes, which Engels assembled posthumously from his notes. Yet in the century following its publication, 'Das Kapital' became foundational to socialist and communist movements worldwide, its ideas invoked, adapted, and distorted by governments controlling roughly a third of humanity by the mid-20th century.