Message to the Members of the Armed Forces.
WE have suffered a great national loss and sorrow in the death of the Commander in Chief, President John Fitzgerald Kennedy. A man who knew war and hated it, he loved peace all the more and sought to make it secure in the world for your children and his. He will be remembered and honored forevermore for his valor and courage in serving that cause of peace which you serve in your faithful vigil for freedom.
Our Constitution provides for the orderly continuity of the civil offices of our Government. In the transition brought upon us by tragedy, there is no interruption in the continuity of that commitment to strength, steadfastness, and selfless sacrifice which has kept us free and the world at peace. As you stand your guard of freedom and peace, you may know that the policies and purposes of your country are unchanged and unchangeable in seeking honorable peace, the friendship and alliance of free nations and the building of a responsible world free of the causes of hatred, division, oppression, and human despair. Praying to be worthy of God's guidance, let us rededicate ourselves to the continuing tasks before us remembering always that the price of our liberty is eternal vigilance.
Lyndon B. Johnson, Message to the Members of the Armed Forces. Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/242709