Final answer:
The law that limits the political activities of federal civil service employees is the Hatch Act.
Step-by-step explanation:
The law that limits the ability of federal civil service employees to participate in certain partisan political activities, such as running for partisan office or attending a political party convention, is the Hatch Act. This legislation was passed in 1939 and its main provision prohibits bureaucrats from actively engaging in political campaigns and from using their federal authority to influence elections.