Simplify the following text for a Grade 11 native English-speaking person.
Original: In the 1920s , Manhattan experienced large arrivals of African-Americans as part of the Great Migration from the American South , and the Harlem Renaissance , part of a larger boom time in the Prohibition era that included new skyscrapers competing for the skyline .
Simplified: In the 1920s , many African-Americans came to live in Manhattan during the Great Migration from the American South , and the Harlem Renaissance .