Source: http://ny.eater.com/archives/2014/04/a_c...

The modern hamburger, as we enjoy it today — principally a commercial object that exists in the public sphere — was first conceived in 1916 in Wichita, KS when line cook Walter A. Anderson combined a beef patty with a custom made bun designed to encapsulate it. This seemingly obvious pairing may indeed have happened at numerous points prior to this moment in domestic kitchens, commercial restaurants, or state fairs, but this occurred in isolation. The standardization required to lay the foundation for a defined, universally recognizable dish was entirely missing.