Developed in two years yet written in about seven weeks, Karl Marx and Friedrich Engals wrote The Communist Manifesto in London, England. Due to the influx of industry in London, Karl Marx (and a group of other revolutionary socialists) considered the impact this type of social change troublesome. To them, the workers should own the businesses--as it had been for as long as human memory--instead of one owner to many workers making little wages. After its publication it became extremely popular (despite not being particularly new information) and it became an important topic of debate. It became the reasons for the fall of the Csars in Russia and later on resulted in the Cold War.

Source: https://www.history.com/this-day-in-history/marx-publishes-manifesto