The SECRETARY OF WAR:
I have to-day considered with more care than when the subject was orally presented me the action of your Department directing letters to be addressed to the governors of all the States offering to return, if desired, to the loyal States the Union flags captured in the War of the Rebellion by the Confederate forces and afterwards recovered by Government troops, and to the Confederate States the flags captured by the Union forces, all of which for many years have been packed in boxes and stored in the cellar and attic of the War Department.
I am of the opinion that the return of these flags in the manner thus contemplated is not authorized by existing law nor justified as an executive act.
I request, therefore, that no further steps be taken in the matter except to examine and inventory these flags and adopt proper measures for their preservation. Any direction as to the final disposition of them should originate with Congress.
Grover Cleveland, Executive Order Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/205402