I don't like to use the adjective "American" when referring to anything peculiar to the USA. "American" can refer to any of the countries in the two American continents. Canadians and Mexicans could justifiably feel offended when we use "American" in the sense of referring to the USA.
The term "Usonian" was coined by James Duff Law and popularized by Wright. I think the term is awkward (but then so is United States of America a ponderous name for a country) but it's recognized so I'll continue to use it until something better becomes accepted.
Wright was the best residential architect ever in my opinion. I've visited several of his iconic homes and they're exquisite from the outside but the interiors tend to be a bit stark, although artistically coordinated. He often insisted on designing the furniture for his homes. While simpatico with the architecture most of it is supremely uncomfortable.
His youthful home designs are less dramatic. He was learning his art and hadn't yet learned to ignore his clients.
His non-residential styles are not my favorites. MOMA is a monstrosity and the Johnson Wax building, while innovative in design, is dated. His work in Japan is far better.
