From the Lawrence Daily Journal-World for May 30, 1974:

Following national trends, Lawrence’s supply of pennies was dwindling dramatically. Several local banks were reporting a two-thirds cut in their penny supplies this month and said they were having to ration pennies to customers. The decrease in the number of pennies in circulation may have been due to hoarders who were saving them in hopes of earning money from the melted-down copper, but profits from melted pennies were minimal, besides being illegal, according to a recent bulletin from the Federal Reserve. Several stores in the area had posted signs urging customers to pay with exact change or to use pennies to pay for items. Employees at two businesses had been asked to bring in extra pennies to help bolster the store’s supply. J. B.’s Big Boy Family Restaurant, 740 Iowa, had lowered the price and tax on food items to the nearest nickel several times in the past few weeks to avoid giving change in pennies.