The trademark MUMBO name was first used by Argia B. Collins, Sr., for use in connection with a barbecue sauce he developed for his Chicago restaurant.
Since Argia's Mumbo Sauce can be traced back to the 1950s (before it showed up at Wings-N-Things) it's speculated that the DC version is a transplanted version of the original Chicago sauce. Recently, after two years of court battles, the Trademark Trial and Appeal Board found that a D.C.-based company could not take the name from its Chicago founder.