What, then, has driven history up to the events of 1848?

Marx & Engels’s famous political pamphlet was written as revolutions were beginning to sweep Europe in 1848. While diectly calling for a particular type of revolution, the Manifesto also offered a philosophy for and explanation of all of history. What, then, has driven history up to the events of 1848? What will the future look like and which groups will shape it? What is the role of the state as described by Marx & Engels?
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