Liberalism has changed its meaning over time. Currently liberalism generally refers to socialism and imposing governments and laws to implement it.
Federalism is nothing more than the layering of government. The United States, as an example, was organized as a federated republic. A republic is government by constitution. A federated republic means layers of government, each with their own constitutions (sometimes called a 'county charter' or 'city charter').
There is no such thing as 'American law'. America is a continent. It has no single government. Of several select nations:
The United States was organized as a federated republic. It is currently a set of independent republics (which I call the States of America (SOA), and a few oligarchies. The federal government has fallen and is currently an oligarchy. It no longer recognizes the Constitution of the United States or the constitution of any State. I call it the Socialist Oligarchy of the District of Columbia (SODC) now. The former States of California is no longer a republic, It no longer recognizes the constitution of the State of California. I call it the Socialist Oligarchy of the Territory of California (SOTC) now. The former State of New York I call the SOTNY now.
The federal government fell on Jan 6th, 2021 with the rejection of State authority over the electoral college, and with the installation of Party Leader(?) of the Oligarchy on Jan 20th.
Canada was organized as a federated oligarchy. It still is. It has no functioning constitution.
Mexico was organized as a federated republic. It still is. It has layered constitutions.
Venezuela is currently a dictatorship. It's current dictator is Nicolas Marudo. It has no functioning constitution.