Port activities remained centered on the Chicago River until well into the 20th Century. In 1909, the City's Harbor and Waterways Commission offered a plan to construct several piers, leading to the construction of Navy Pier. Four years later, in 1913, the General Assembly passed legislation enabling the City to acquire, develop, and own and operate port facilities within the city limits.
The modern history of the Port of Chicago began in 1921, when the State Legislature passed the Lake Calumet Harbor Act authorizing the City to build a deep water port at Lake Calumet. Late that year, the City adopted the Van Vlissingen Plan, which remains the Port's basic framework for commercial shipping and industrial development.
Regularly scheduled overseas shipping service was established in 1935 and in 1941 the Chicago Plan Commission published an industrial development plan for the Lake Calumet area. Five years later, Congress authorized the Calumet-Sag Project to facilitate barge traffic between Lake Michigan and the Illinois and Mississippi Rivers.
In 1951, the General Assembly created the Chicago Regional Port District to oversee harbor and port development. A year later, the State Legislature established the District as an independent municipal corporation with title to approximately 1500 acres of marshland at Lake Calumet. A plan released in 1953 called for construction of a turning basin, docks, grain elevators, and public terminals and re-named the harbor the Senator Dan Dougherty Harbor with the goal of completing construction by the opening of the St. Lawrence Seaway in 1958. The Port opened with great fanfare in 1958, well before the Seaway was officially dedicated on June 26, 1959.In 1960, in exchange for a long-term lease, Union Tank Car created an enlarged deep water turning basin and additional slips along the east side of the harbor and eventually built 91 liquid storage tanks with a combined capacity of 800,000 barrels.
In 1972, Navy Pier officially ceased operations of commercial shipping at that location. In 1978, the Port District acquired an additional 190 acres at the mouth of the Calumet River, built two new terminal sheds and rechristened this site "Iroquois Landing," giving the District a second major waterfront site for the future.
Since 1979 the Iroquois Landing Terminal has always been regarded as the finest deep draft and shallow draft terminal on the Great Lakes and inland river system with unparalleled access by ocean, lake and river vessels.
Today, the Illinois International Port moves more general cargo than any other port on the Great Lakes, with an annual total (waterborne) tonnage of over 19 million tons, maintaining Chicago’s place among the top 36 ports in the nation. The goods, products, natural resources and finished goods are shipped via the Port throughout the world and are received from all corners of the globe. The Port of Chicago truly brings the world markets to Chicago’s doorstep and Chicago’s products to the world.