Bawdy ballads, and folk songs in general, come from a wide variety of places. There are, of course, American ballads written by Americans. But a greater number of the ballads can be traced to the immigrants that settled America, bringing their favorite songs with them. The songs changed over time to reflect American styles of music, and Americans' unique brands of bawdy behavior. Many folk songs sung in America, bawdy and otherwise, come from the British Isles, the source of Americas' first great wave of immigrants.
Other folk songs have not changed that much over the years. They have achieved their status as folk songs because people love them and sing them...they are the songs that "everybody knows."…they have become songs The Bastard King of England is an example. We even know the author of this ballad--English writer Rudyard Kipling. It is possible that Kipling was denied a knighthood because of his venture into bawdy balladry.
But most folk songs do evolve, and the evolution is by no means limited to the distant past. The 1960s folk singer Woody Guthrie created an anti-Hitler rallying cry, Round and Round Hitler's Grave, from the square dance tune Old Joe Clark.
In order for a ballad to be passed down, it must not only be simple and catchy to sing but easy to remember. It must have a theme that people can relate to. The themes of the songs on this site--love, lust, the treachery of lovers--are certainly slow to change. Enjoy !