January 31, 1902
All officers and employees of the United States of every description serving in or under any of the Executive Departments and whether so serving in or out of Washington are hereby forbidden either direct or indirect, individually or through associations, to solicit an increase of pay, or to influence or to attempt to influence in their own interest any legislation whatever, either before Congress or its Committees, or in any way save through the heads of the Departments in or under which they serve, on penalty of dismissal from the government service.
THEODORE ROOSEVELT
Theodore Roosevelt, Executive Order Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/206937