Nearly 50 years after his death, Louis Armstrong remains one of the 20th century's most iconic figures. Popular fans still appreciate his later hits such as "Hello, Dolly " and "What a Wonderful World," while in the jazz community, he remains venerated for his groundbreaking innovations in the 1920s. The achievements of Armstrong's middle years, however, possess some of the trumpeter's most scintillating and career-defining stories. But the story...