In March 1947 US president Harry Truman signed Executive Order 9835, laying down a ‘Loyalty Program’ for government employees. This order initiated an investigation of around three million government employees:

“Whereas each employee of the Government of the United States is endowed with a measure of trusteeship over the democratic processes which are at the heart and sinew of the United States; and

Whereas it is of vital importance that persons employed in the Federal service be of complete and unswerving loyalty to the United States; and

Whereas, although the loyalty of by far the overwhelming majority of all Government employees is beyond question, the presence within the Government service of any disloyal or subversive person constitutes a threat to our democratic processes; and

Whereas maximum protection must be afforded the United States against infiltration of disloyal persons into the ranks of its employees…

There shall be a loyalty investigation of every person entering the civilian employment of any department or agency of the executive branch of the Federal Government…

The investigations of persons entering the employ of the executive branch may be conducted after any such person enters upon actual employment therein, but in any such case the appointment of such person shall be conditioned upon a favourable determination with respect to his loyalty…

An investigation shall be made of all applicants at all available pertinent sources of information and shall include reference to:

a. Federal Bureau of Investigation files.

b. Civil Service Commission files.

c. Military and naval intelligence files.

d. The files of any other appropriate government investigative or intelligence agency.

e. House Committee on un-American Activities files.

f. Local law enforcement files at the place of residence and employment of the applicant, including municipal, county and state law enforcement files.

g. Schools and colleges attended by applicant.

h. Former employers of applicant.

i. References given by applicant.

j. Any other appropriate source.

Whenever derogatory information with respect to loyalty of an applicant is revealed, full field investigation shall be conducted. A full field investigation shall also be conducted of those applicants, or of applicants for particular positions, as may be designated by the head of the employing department or agency… based on the determination by any such head of the best interests of national security…

The head of each department or agency shall appoint one or more loyalty boards, each composed of not less than three representatives of the department or agency concerned, for the purpose of hearing loyalty cases arising within such department or agency and making recommendations with respect to the removal of any officer or employee of such department or agency on grounds relating to loyalty…”