What were Marx and Engels objections and arguments when writing the Communist Manifesto?

In the Communist Manifesto, Marx and Engels critized the 19th century industrial capitalist society. They stated that the new ruling class, the bourgoisie, exploited workers. They also briefly surveyed the transformation of Europe from a medieval economy to a capitalist economy and the social and political changes brought about by that development. They envisioned a particular mission for the class of the workers, or the proletariat, that would rise against the capitalist opression and make revolutionary changes to bring justice. In the Manifesto, they summarize what Communist ideas really are in order to dispel misinterpretations.