On the recordFebruary 20, 1966
As a mark of respect to the memory of Fleet Admiral Chester W. Nimitz, it is hereby ordered, pursuant to the provisions of Section 4 of Proclamation 3044 of March 1, 1954, that until interment the flag of the United States shall be flown at half-staff on all buildings, grounds, and naval vessels of the Federal Government in the District of Columbia and throughout the United States and its Territories and possessions.
Source
presidency.ucsb.edu
