12/31/1967
https://www.presidency.ucsb.edu...
"I am very proud to accept this Liberty Bell this morning."
"If we can't, we will take other measures. It may be more costly."
"And it will help the government to contain costs—costs that, ultimately, are borne by the taxpayers."
"Now, Therefore, I, Lyndon B. Johnson, President of the United States of America, do hereby designate the period of October 10 through October 15, 1966, as National ZIP Code Week."