Final answer:
Moms Mabley was best known for her stand-up comedy, which was part of a larger movement where African American performers shaped the early 20th-century entertainment industry.
Step-by-step explanation:
Moms Mabley, a renowned comedian, was best known for her stand-up comedy. She was part of an era when musical theatre grew from vaudeville traditions and became a significant form of commercial theatre. Notable African American performers like Bert Williams and George Walker contributed to this evolution, with Williams becoming a trailblazing comedian in Ziegfeld's Follies. Moms Mabley's career reflected the vitality and influence of African American performers in the comedy and entertainment industry during the 20th century.