 Contributing factors leading to the Harlem Renaissance were the Great Migration of African Americans to northern cities, which concentrated ambitious people in places where they could encourage each other, and the First World War, which had created new industrial work opportunities for tens of thousands of people.Factors leading to the decline of this era include the Great Depression.In 1917 Hubert Harrison, "The Father of Harlem Radicalism," founded the Liberty League and "The Voice", the first organization and the first newspaper, respectively, of the "New Negro Movement."