As with many movements in the arts, the Harlem Renaissance was influenced heavily by the economics of its time. During the early 20th century, America like much of the world was moving from an agriculturally based economy to a more industrial. Cities in the North were leading the way in this change, so many African Americans in the less affluent South started to seek higher paying jobs above the Mason Dixon line.
U.S. policy on immigration also prompted this northern migration, as the government began limiting the numbers of immigrants from entering the country. This policy along with the industrialization above and a promise of a better more equal life caused African American populations in major northern cities to nearly double by the 1930s.
Socially, writers such as Booker T. Washington had pushed the notion forward of a well educated and proud African American man instead of the backward stereotypes that many people, including African Americans, had accepted from their society. This push towards independent thinking and pride in leadership of new lives also helped the Harlem Renaissance blossom.
Beyond the extensive reach of WWI general influence, the end of the war in 1919 also brought racial relations to a head. White soldiers returned and struggled to accept the changing roles of African Americans. African American soldiers returned from fighting the respect they earned on the battlefield and once again were treated as second class citizens by fellow Americans they defended. In 1919, 25 race riots took place and over 75 lynchings were reported.
Finally, Harlem itself influenced the movement as it became the center of African American life and culture in the northeast. The neighborhood had once been a wealthy white collection of homes and recently experienced a housing bubble and it was left with foreclosed properties that were affordable. The comfort and excitement offered by the neighborhood continued to attract African American leaders in all walks of life through the 1920s. The population quadrupled in that decade.