Context of Act Providing for Creation of the Saint Lawrence Seaway Development Corporation To Construct Part of the Saint Lawrence Seaway in United States Territory in the Interest of National Security; Authorizing the Corporation To Consummate Certain Arrangements with the Saint Lawrence Seaway Authority of Canada Relative to Construction and Operation of the Seaway; Empowering the Corporation To Finance the United States Share of the Seaway Cost on a Self-liquidating Basis; To Establish Cooperation with Canada in the Control and Operation of the Saint Lawrence Seaway; To Authorize Negotiations with Canada of an Agreement on Tolls; and for Other Purposes