Complex sentence: In 1916 he started helping African Americans resettle in Omaha and by 1917 he helped found the Hamitic League of the World, who in 1918 published his pamphlet "Children of the Sun" which highlighted the African presence in classical Egyptian, Asian and European civilizations.
Split into simpler sentences: In 1916 he started helping African Americans resettle in Omaha and by 1917, he helped found the Hamitic League of the World. In 1918 the League published his pamphlet "Children of the Sun", which highlighted the African presence in classical Egyptian, Asian and European civilizations.