Why did socialism appeal to and mobilize the working class?

In order to understand why Socialism became very popular, we need first to say that among intellectuals became first very popular as antecedents for those who were motivated by the progress of industry and technologic growth. This first form of socialism developed only to a very selected class of idealist and educated man that were seeking to apply the benefits of the advances in science to make a society more equal in terms of quality of life for all the social classes. We can then trace back socialism to works of the sociological-political thought of Henri de Saint-Simon, August Comte, among others in the late 1700s.

However, it was until the works of Karl Marx, mainly "Das Kapital" (published in 1867) that inspired the political thought of working class first in the aftermath of the first world war in Europe lead by the consequences of the disaster as a way to deal with the misery of the time. Socialism was seen as the alternative to the capitalism exposed by the English, French, U. S. and later it began to conflict with the dynamics of the national socialist Germany and Italy. Since socialism as an ideological movement stresses the importance of the workers in the role they play in society, it promises a world where they will be the owners of the means of production in order to achieve a centralized or rationalized means of planning the economy and therefore it promises an equal distribution of wealth.

The main appeal for the socialists is to see a world where social injustices are practically nonexistent, and where workers are on the conditions to establish a society were everyone is no longer being subject to a savage process of "alienation". Workers can fully develop as subjects of a society where they are no longer seen as objects of interchange in a capitalist market. They will no longer be just the workforce but the leaders of a new model of society to come where everyone has minimal requirements for also developing a spiritual and enriching the cultural side of societies.