03/31/1965
https://www.presidency.ucsb.edu...
"It is with regret that I have received your resignation."
"My regret at your leaving is tempered by satisfaction in the knowledge that you intend to continue your service to your country."
"This is a very happy and historic occasion for all who love the great American outdoors, and that, needless to say, includes me."
"I believe the significance of this occasion goes far beyond these bills alone."