In 1949, Louis Armstrong, a notable New Orleans native, came back to town to be anointed king of Zulu. He wore blackface and a grass skirt. For the last 100 years, the Zulu Social Aid and Pleasure Club has carried on a Mardi Gras tradition. On Feb. 24, the raucous Zulu parade will roll down the streets of New Orleans, drawing a range of reactions from the crowd.