D. Minnesota April 1969 casesCity of Owatonna v. Chicago, Rock Is. Pac. R.R.Dairy Foods Inc. v. Farmers Co-op. CreameryUnited States v. AlexanderKnutson v. Selective Service System, Local Bd. No. 36, Hennepin CountyDuluth Bd. of Trade v. HeadGendreau v. Finch