I'm not sure if you meant the highest Law or the highest Court. I know of no such law being considered the "highest law". However, the highest Court is the US Supreme Court.
Highest law= US Constitution
federal law
Constitution
The supreme law of the US is the Constitution. It establishes the framework for the federal government and outlines the rights and freedoms of the American people. It is the highest law in the country and all other laws must be in accordance with it.
The Constitution.
congress
congress
1787
The Constitution and it's amendments
US
The constitution of a country is its highest law. It's a set of rules and principles according to which a country is governed.
The highest law in every country is the Constitutions. This also applies in South Africa. In the South African constitution, there is the supremacy clause which establishes that all other laws are subject to the Constitution.
the highest law officer in this country (united states) would be the Attorney general, the head of the judicial branch of government, The Attorney General is the head of every federal law enforcement branch as well as the court systems.