Which department is in charge of American prisons?

American prisons are managed by the Federal Prison Service of the Ministry of Justice;

The U.S. Department of Justice is a department of the U.S. government, and its ministers enjoy cabinet status. The task of the U.S. Department of Justice is to ensure the enforcement of laws, safeguard the legitimate interests of the U.S. government, and ensure that laws are equal to all American citizens. Its minister is the attorney general of the United States.

Prison Bureau is the administrative law enforcement organ in charge of prisons, which is the abbreviation of "Prison Administration".