I used to sell furniture. If you are looking for reproductions, you can find chairs like that at any Ethan Allen store, or any store that carries Thomasville, Henredon, or Baker upholstery. Smaller manufacturers like the Sam Moore chair company used to make them.
Quite often you can find used chairs in this style at second hand and antique shops, because the style was popular during the colonial revival of the 20's and again in the 40's.
Obviously, an antique from the 18th century is worth thousands (and those chairs President Bush has are probably true antiques) but there are plenty of sources to get similar styles. I hope this helps.
Thanks MM. I have checked with Ethan Allen and a host of other stores in my area but I can't seem to find just the right one. Either the back is too high, or the seat is too wide, or the arms are different. I shall keep pursuing this though as the other chairs I have decided on - at Ethan Allen - haven't come in yet. They started advertising them in April and they still don't have any in the store. Errrrrrr. Thanks again for the info. I'll keep you posted.