This article studies the changes in the popular struggle during the years between the  Civil War  of 1891 and the massacre at the Santa María School in Iquique ( L901), from primary forms of social protest to strikes and labor petitions. The analysis of numerous mass movements permit an insight into the points  of contact, the breaks and impasses  in the transition from mob riots to te modern workers movement. It explain when and why the violence  of the underclass slowly decreased and gave way to orderly petitions, disciplined acts  of pressure and an increasing tendency to negotiation, and establishes that the turning point in this evolution in the forms  of struggle took place between 1902 and 1905. Although the perspective is national, attention is centered on three key areas: the nitrate region  in the North, the principal cities  of Central Chile and the coal mining region round the Gulf of Arauco.