During the 1920s and early 1930s American expatriots filled the streets of Paris. Throughout the first twenty years of the century European artists had flocked to Paris, considering it the cultural center of the Western World. Feeling alienated from the conservative post-war sensibilities of their country, many young Americans moved there, hoping to take part in the experimental advances of the artistic community. Though it was only to last until the start of World War II, this time saw the beginning of a number of the major European movements including Modernism, Dadaism, and Surrealism. By 1935, many artists had left Europe for the safer shores of New York and Los Angeles, where their earlier European work became the foundation for many of the major advances in American creative culture of the twentieth century.