Clive it used to be easy to obtain a US licence, and it has been a number of years since I last followed this route. You simply made an appointment at a FSDO and took your current foreign licence and medical and a temporary airman certificate was issued. This was basically worthless commercially until you took a flight test with an FAA designate examiner. There is also a requirement with the FAA licence to undetake a biennial flight review to keep the licence active.
Current FAA rules-
https://www.faa.gov/licenses_certifi..._verification/