History

The best concertina history that I know of was put together by the Czech Area Concertina Club up in New Prague, Minnesota, with the book The Chemnizter Concertina, A History and an Accolade by LaVern Rippley.  However, if you are interested in more about the history, go here.

Basically, the famous inventor, Charles Wheatstone, designed a concertina (1844), or squeezebox in England.  This is the ancestor of the Irish and English concertinas.  Some years before, in Chemnitz, Germany, Carl Uhlig came up with a different design that we call the Chemnitzer Concertina (1835).  The first ones had 5 buttons on the right and 5 buttons on the left, but drawing and pressing the bellows gave two different pitches.  So this is the "10-button" but "20-tone" or "20-key".  As Uhlig continued to develop his design, nearby competition in also came up with other designs - Carl Zimmerman in Carlsfeldt (1832) and Heinrich Band in Krefeld (1846), whose bandonion became the famous bandoneón of Argentina's tango music.  I haven't heard much about the Carlsfeldt other than Zimmerman got bought out by Arnold, but I think they used either the Uhlig or Band design.

From then to now, the bare bone history is that Chemnitzer concertinas were exported to the US, and then manufactured in the US.  The German factories were all shut down for WW2, and never re-opened.  Thus, Chemnitzer concertinas became only made in the US.

Today, the Chemnitzer Concertina is mostly a footnote to the bandoneón, and is no longer manufactured except by a few handmade ones in Wisconsin and Minnesota - most notably JBM Sound (Jerry Minar's business which owns the Hengel brand) in New Prague, MN and Dan Gruetzmacher in Wausau, WI.  Here it is a cultural remant, played in communities with German or Polish heritage, and is tenuously passed down through the generations by players teaching other players.

For more details, I highly recommend this site on the bandoneón, which has a wealth of information about both the bandoneón and the concertina.