Final answer:
The United States Marshals Service is responsible for transporting federal prisoners and ensuring the security of federal courthouses. It is the oldest federal law enforcement agency and supports the judiciary by maintaining the integrity of the Constitution and federal laws.
Step-by-step explanation:
The entity responsible for the transporting of federal prisoners and the security of federal courthouses is the United States Marshals Service (USMS). The USMS is a critical component of the federal justice system and falls within the executive branch of the U.S. government. It is part of the Department of Justice and operates under the direction of the Attorney General.
In addition to prisoner transport and courthouse security, the Marshals Service also handles fugitive operations, asset forfeiture, and witness security. It has a storied history as the oldest federal law enforcement agency, having been established by the Judiciary Act of 1789. Its roles have evolved over time, but its foundational duties remain to ensure the effective operation of the judiciary and to maintain the integrity of the Constitution and federal laws.