John Kennedy actually said...
Now, Therefore, I, John F. Kennedy, President of the United States, under and by virtue of, the authority vested in me by the Constitution and laws of the United States, including; Chapter 15 of Title 10 of the United States Code, particularly Sections 332, 333 and 334 thereof, do command all persons engaged in such unlawful obstructions of justice, assemblies, combinations, and conspiracies to cease and desist therefrom and to disperse and retire peaceably forthwith.
Context
Proclamation 3554—Obstructions of Justice in the State of Alabama
09/09/1963