Modernism is a philosophical movement that, along with cultural trends and changes, arose from wide-scale and far-reaching transformations in Western society during the late 19th and early 20th centuries. Among the factors that shaped modernism were the development of modern industrial societies and the rapid growth of cities, followed then by reactions of horror to World War I. Modernism also rejected the certainty of Enlightenment thinking, and many modernists rejected religious belief. 

Modernism, in general, includes the activities and creations of those who felt the traditional forms of art, architecture, literature, religious faith, philosophy, social organization, activities of daily life, and even the sciences, were becoming ill-fitted to their tasks and outdated in the new economic, social, and political environment of an emerging fully industrialized world. The poet Ezra Pound's 1934 injunction to "Make it new!" was the touchstone of the movement's approach towards what it saw as the now obsolete culture of the past. In this spirit, its innovations, like the stream-of-consciousness novel, atonal (or pantonal) and twelve-tone music, divisionist painting and abstract art, all had precursors in the 19th century. 

A notable characteristic of modernism is self-consciousness and irony concerning literary and social traditions, which often led to experiments with form, along with the use of techniques that drew attention to the processes and materials used in creating a painting, poem, building, etc. Modernism explicitly rejected the ideology of realism and makes use of the works of the past by the employment of reprise, incorporation, rewriting, recapitulation, revision and parody.
when did artists all have precursors?
19th century