Harry Truman actually said...
Any person who in order to perform active service with the military or naval forces of the United States has left, or leaves, a position (other than a temporary position) which is covered into the classified civil service under section 1 of this order shall be reinstated in the department or agency to the position in which he last served or to a position of like seniority, status, and pay in the same department or agency, and upon reinstatement thereto may acquire a classified civil-service status.
Context
Executive Order 9678—Amendment of Executive Order No. 8743 of April 23, 1941, Extending the Classified Civil Service
01/13/1946