Beukema and Saint Lawrence Seaway proponents were convinced a nautical link would lead to development of the communities and economies of the Great Lakes region by permitting the passage of oceangoing ships. In this period, exports of grain, along with other commodities, to Europe were an important part of the national economy. Negotiations on the treaty resumed in 1938, and by January 1940 substantial agreement was reached between Canada and the United States. By 1941, President Roosevelt and Prime Minister Mackenzie King made an executive agreement to build the joint hydro and navigation works, but this failed to receive the assent of the U.S. Congress. Proposals for the seaway were met with resistance; the primary opposition came from interests representing harbors on the Atlantic and Gulf coasts and internal waterways and from the railroad associations. The railroads carried freight and goods between the coastal ports and the Great Lakes cities.