US system is different. American culture is very car oriented. Even if there is high speed rail available in the US VERY FEW PEOPLE will be using them, so it's not viable in the US.
Moreover the vast presence of airports all around the country even in the most remote areaa makes it even more unviable. There are over 19,633 airports in the US , by far the largest in the world and most develop aerospace industry on earth.
www.google.co.uk
Even more Reason there was never a need for high speed rail in the US, unlike in Europe, Japan.