Much of the NH TC class is Japanese made by Shiburu(sp?) under contract to CNH specs to CNH designs, and then assembled in Georgia. But remember, CNH is not an American company, it is owned by Fiat. The larger machines (combines, etc) are made here.
Some of the new JD CUTS are pretty much American made machines. Some are made by Yanmar under contract to JD specs to JD design, many of those are assembled in Georgia. JD is probably the most American of the traditional style CUTs in terms of being made here. And it is, for the most part, American owned.
Cub Cadet is owned by MTD, some are made here, some of the larger units are made in Korea by Kioti. There may be someone else making their midsized units. They source out engines from 3rd party mfgs.
Ventrac is designed, and built in Ohio. But uses engines from several sources.
Power Trac is designed and built in West Virginia. Just like Ventrac, they rely on 3rd party engine manufacturers.