On this day in 1867, volume one of Karl Marx’s Magnum Opus, 'Das Kapital' first appeared in Germany. Subsequently published in all the world’s major languages and studied widely by workers it was often referred to as “The Bible of the working class”. While lengthy, it is definitely worth a read at some point as it is still unsurpassed as an analysis and critique of capitalism.
The full text is also available online for free at, https://libcom.org/library/capital-karl-marx