Copies of the US Constitution are readily available. I have a number of inexpensive copies of the document - bought when I have been visiting the USA. Online there are a number of sites whichgive the text. The House of Representatives site is available here.
An annotated Constitution is available here, which has been prepared by the Congressional Research Service. This has great detail - if you wish an outline of the main structure of the Constitution, one is available here.
It can be very useful to study the US Constitution, and not only if you are a US citizen. For students of constitutions generally it is a useful model. It is short, sharp and to the point. The structure is clear and logical. It may not be perfect, but does set out a structure of checks and balances.
