This is a brief overview of the history of calls that have been used to hunt turkeys in America. For brevity's sake, the main discussion is limited primarily to the 19th - 21st centuries, although certain devices such as the "bone flutes" discovered in archaeological dig sites have been dated back to prehistoric North America. NOTE: The following historical info is accurate to the best of my limited knowledge. I will include references where it seems necessary, and eventually add a list of sources; however, I would be happy to pass on sources to anyone who is interested. Also, anyone who finds errors is welcome to straighten me out.
Recent Wingbone Yelper. Jordan's would have looked similar, but would have most likely attached the radius to pieces of cane with waxed thread (call and photo courtesy of Jesse H).
This type of call is operated by scraping the peg against the slate to produce the various standard hen calls. The "peg" or dowel striker is typically attached to a larger dowel or block of wood that has been hollowed out to produce a sound chamber. These days, many substances have been used to replace slate as a striking service--notably aluminum and glass--while carbon and acrylic rods are often used as strikers, particularly on non-slate surfaces.
This "Pure Poison" Tony Reynolds peg-and-pot features glass as a striking surface, while the Ron Clough call on the right sports a slate surface and "stick (dowel)-and-corncob" striker.
More information on turkey calls and their history, as well as pictures of contemporary callmakers and their work, can be found online at Custom Calls Online. A list of books related to turkey calls, callmakers, and their history, can be found on my Resources page. The books by Howard Harlan and Earl Mickel are highly recommended.