Final answer:
Jazz dance as a professional form began to emerge after World War I, during the Jazz Age and was heavily influenced by the Harlem Renaissance and the Great Migration.
Step-by-step explanation:
Jazz dance as a professional form began to develop and gain widespread popularity after a significant historical event: the end of World War I. This era, known as the Jazz Age, was a time of great cultural change and experimentation within the United States, especially throughout the 1920s.
The Harlem Renaissance played a crucial role in this development, creating a vibrant cultural scene where jazz music and dance flourished. Jazz spread from the African American communities in cities like New Orleans, Chicago, and particularly Harlem in New York, where it became a part of the dynamic nightlife.
This movement was further propelled by the Great Migration, which brought hundreds of thousands of African Americans from the South to the Northern cities and influenced the music and culture in profound ways.