How did Louis Armstrong get the nickname “Satchmo?”

Louis had many nicknames as a child, all of which referred to the size of his mouth: “Gatemouth,” “Dippermouth,” and “Satchelmouth.” During a visit to Great Britain, Louis was met by Percy Brooks, the editor of Melody Maker magazine, who greeted him by saying, “Hello, Satchmo!” (He inadvertently contracted “Satchelmouth” into “Satchmo.”) Louis loved the new name and adopted it for his own. It provides the title to Louis’s second autobiography, is inscribed on at least two of Louis’s trumpets, and is on Louis’s stationery.