In the United States, the federal civil service was established in 1871. The Federal Civil Service is defined as "all appointive positions in the executive, judicial, and legislative branches of the Government of the United States, except positions in the uniformed services." . In the early 19th century, positions in the federal government were held at the pleasure of the president—a person could be fired at any time. The spoils system meant that jobs were used to support the American political parties, though this was gradually changed by the Pendleton Civil Service Reform Act of 1883 and subsequent laws. By 1909, almost two-thirds of the U.S. federal workforce was appointed based on merit, that is, qualifications measured by tests. Certain senior civil service positions, including some heads of diplomatic missions and executive agencies are filled by political appointees. Under the Hatch Act of 1939, civil servants are not allowed to engage in political activities while performing their duties.