Not a definitive source, but here's FATCA for example: https://www.treasury.gov/resource-center/tax-policy/treaties/Documents/FATCA-Agreement-BVI-6-30-2014.pdf

Not a definitive source, but here's FATCA for example: https://www.treasury.gov/resource-center/tax-policy/treaties/Documents/FATCA-Agreement-BVI-6-30-2014.pdf https://www.treasury.gov/resource-center/tax-policy/treaties... > The term “U.S. Territory” means American Samoa, the Commonwealth of the Northern Mariana Islands, Guam, the Commonwealth of Puerto Rico, or the U.S. Virgin Islands. https://en.wikipedia.org/wiki/Territories_of_the_United_States https://en.wikipedia.org/wiki/Territories_of_the_United_Stat... And there's plenty of references to legal documents clearly stating or implying that territories are in fact not sovereign entities (e.g. https://en.wikipedia.org/wiki/Puerto_Rico_v._Sanchez_Valle https://en.wikipedia.org/wiki/Puerto_Rico_v._Sanchez_Valle) And obviously there's only one Disctrict. The District of Columbia. So it's actually fairly complex to define "the United States", because the answer is generally "it depends on the context"