Final answer:
The Privacy Act of 1974 is the act that requires federal government agencies to make information in an individual's file available to them.
Step-by-step explanation:
The act that requires federal government agencies to make information in an individual's file available to him or her is the Privacy Act of 1974. This act prevents the unauthorized disclosure of personal information held by the federal government. It ensures that individuals have the right to access and review their own records, and it sets the guidelines for how government agencies collect, use, and protect personal information.