Lyndon Johnson actually said...
It is hereby ordered that any income, excess profits, estate, or gift tax return for the years 1947 to 1968, inclusive, shall, during the Ninetieth Congress, be open to inspection by the Committee on Government Operations, House of Representatives, or any duly authorized subcommittee thereof, in connection with its studies of the operation of Government activities at all levels with a view to determining the economy and efficiency of the Government.
Context
Executive Order 11332—Inspection of Income, Excess-Profits, Estate, and Gift Tax Returns by the Committee on Government...
03/06/1967