Question

by the 1870's socialist ideas spread through Europe justify

Answer 1

The ideas of socialism were established with the advent of liberals and radicals.

The factory labour not only comprised of men but now women and children were also an active participant

Further an international body, namely - the Socialist International was established by socialists to coordinate their efforts. 

Funds were set up to help the poor families and provide them their rights. 

Various democratic parties were also formed to promote socialism.