Most federal agencies are created by Congress through statutes called "enabling acts" which define the scope of an agency's authority. Because the Constitution does not expressly mention federal agencies (as it does the three branches), some commentators have called agencies the "headless fourth branch" of the federal government. However, most independent agencies are technically part of the executive branch, with a few located in the legislative branch of government. By enacting the Administrative Procedure Act (APA) in 1946, Congress established some means to oversee government agency action. The APA established uniform administrative law procedures for a federal agency's promulgation of rules and adjudication of claims. The APA also sets forth the process for judicial review of agency action.