Who can create a federal court system without an amendment being added

US Supreme Court

Explanation:

The United States Constitution established only one federal court—the United States Supreme Court. Beyond this, Article III of the Constitution left it to the discretion of Congress to “ordain and establish” lower federal courts to conduct the judicial business of the federal government.

the federal constitution of the united mexican states of 1824 was enacted on october 4 of 1824, after the overthrow of the mexican empire of agustin de iturbide. in the new constitution, the republic took the name of of united mexican states. it was replaced by the federal constitution of the united mexican states in 1857.