An American chair  

SDR, what makes you say this is American? Definitely looks more Scandinavian in form...

That was a poor choice of words; I should have said that the chair is in America. It is one of a set recently purchased for this house:
http://www.curbed.com/2016/3/3/11152970/frank-lloyd-wright-homes-for-sale
The new owner thought the chairs would look good in the house; it then developed that they look just like, and may even be, the same chairs formerly a part of the household furnishings of a previous owner, who came to visit and was surprised to find them there.
As a Wright fan, I thought it would be nice to be able to identify them for the new owner . . .

Looking for them when I have time, but nothing yet.
That "X" shaped seat support and the basic form of the backs really reminds me of the Wegner elbow chair. This is obviously not the correct attribution, but they just have such a similar feel, based on the pictures...

Thanks for your help, Zephyr !
There's no rush, and it's not a high priority. Just curious, though -- sooner or later it would be nice to know.

It's a little too hard to tell, from the picture, exactly how the leg intersects the back.
Any better pictures of them? The "X" brace reminds me of something I'm work on presently. But the (top) back looks much more refined.

That's a handsome home, SDR.
Fondly,
Aunt Mark

Here's the best I can do. The back appears to be triangular in section, with the leg entering the lower bevel. The end of the back is also beveled.

@SDR,
My lovely sister recently stayed in a FLW designed hotel in Iowa ( I'll look for my postcard and token from the gift shop..) , Mason City I think? She stayed an extra few nights to absorb the love. Used to be a bank, possibly. Frank was filling in for the bartender most nights. I shall be sure to check in, and check it out soon. Check.
Heck,
Aunt Mark, Friend of Frank (FoF)

Yes -- the Park Inn, now redundantly called the Historic Park Inn.
http://www.stoneycreekhotels.com/hotel/travel/masoncity-parkinn/home.do

That's it!
Until then,
Aunt Mark
ps it looks like kd lang was bartending that night. I was thinking that the decor would be more authentic. Hmmm.

No. And in the banking hall -- I don't know what it's used for now -- someone decided a copy of a Wright stained-glass design would look good as a carpet, at a giant scale. Whew . . .

Sometimes two Wrights make a wrong.

Chair was designed by H.W. Klein for Bramin Møbler in 1964.

Model 250 no less. Don't know how I am ever going to beat Leif to an ID ..... some day, some day......
https://www.1stdibs.com/furniture/seating/dining-room-chairs/danish-teak...