I'm not going to speculate as to how Arthur acquired his nickname - but anyone with a name like that deserves the utmost respect !!
Arthur led the classic bluesman's life, migrating from the Deep South to Chicago at the end of the Great Depression and earned his living by playing on the streets. But his talent stood out, and by 1941 he was a recording artist at RCA.
His main claim to fame, although very few people realise it, is as the author of the simple but powerful blues "That's All Right, Mama", which became Elvis Presley's first hit for the Sun label in 1954. Arthur was indirectly responsible for the very beginnings of rock and roll - an unsung hero if ever there was one.
Elvis also recorded two more of Arthur's songs - "My Baby Left Me" and "So Glad You're Mine".

Arthur died in 1974, aged 69