By virtue of and pursuant to the authority vested in me by section 179 of the Revised Statutes of the United States (5 U.S.C. 6), and in the interest of the internal management of the Government, it is ordered as follows:
1. (a) The Under Secretary of the Interior shall perform the duties of the Secretary of the Interior in case of the death, resignation, absence, or sickness of the Secretary of the Interior.
(b) The ranking Assistant Secretary of the Interior when both of the Assistant Secretaries are present, otherwise the Assistant Secretary of the Interior who is present, shall perform the duties of the Secretary of the Interior in case of the death, resignation, absence, or sickness of the Secretary and Under Secretary of the Interior.
(c) The Solicitor of the Department of the Interior shall perform the duties of the Secretary of the Interior in case of the death, resignation, absence, or sickness of the Secretary, the Under Secretary, and the Assistant Secretaries of the Interior.
2. The Assistant Secretary of the Interior whose commission bears the earlier date, or, if the commissions of the Assistant Secretaries bear the same date, the Assistant Secretary who took the oath of office on the earlier date, shall be the ranking Assistant Secretary of the Interior for the purpose of paragraph 1(b) of this order.
3. This order supersedes Executive Order No. 9432, dated March 28, 1944.
HARRY S. TRUMAN
THE WHITE HOUSE,
June 14, 1947
Harry S Truman, Executive Order 9866—Designation of Officers to Act as Secretary of the Interior Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/279023