Historically, societies have always located near water, due partly to the
fact that water enables more efficient travel compared to going over land.
Waterways are critically important to the transportation of people and
goods throughout the world. The complex network of connections between
coastal ports, inland ports, rail, air, and truck routes forms a
foundation of material economic wealth worldwide.
Within the United States, waterways have been developed and integrated
into a world-class transportation system that has been instrumental in the
country’s economic development. Today, there are more than 17,700
kilometers of commercially important navigation channels in the lower 48
Early History of Water-based Transportation
The historical development of water-based transportation is connected to
the importance of domestic and international trade. Early exploration of
North America identified large amounts of natural resources such as
fisheries, timber, and furs. Trade centers were established along the
east coast of North America where goods could be gathered together and
ocean vessels could transport them to consumers in Europe and other
foreign areas. The success of commercial trading companies spurred the
Waterways in developing countries are critical avenues for local
and regional commerce. Fruit and vegetable vendors flock to floating
markets on rivers and canals, such as this one in Bangkok, Thailand.
more colonial settlements that in turn resulted in additional increases
in population, economic activity, and trade.
From the sixteenth to the eighteenth centuries, small subsistence farms
were prevalent among the American colonies. Eventually larger farms
emerged and produced crops such as wheat, tobacco, rice, indigo, and
cotton that were commercially marketable in Europe. Ocean vessels
transported the bulk, low-value goods from the colonies to Europe and
returned with high-value, low-density goods such as inks, linens, and
finished products that had a much higher return on the investment per
Agricultural production continued to grow and support the growing
colonies’ economic development. The speed and low cost of
transporting goods by water influenced the locations of population
settlements near navigable water (rivers, lakes, canals, and oceans).
Goods produced on inland farms were transported via inland waterways to
the coastal ports. Goods shipped by smaller vessels from surrounding
ports were transported to New York, Boston, and Philadelphia, and
exported on larger oceangoing ships. These ships from the smaller ports
then transported imported goods back to the surrounding ports.
During the 1700s, the British government passed many acts, such as the
Navigation Acts and the Stamp Act of 1765, designed to collect taxes
from the colonists. The acts affected trade, and were met with
opposition from the colonist. In Philadelphia during the fall of 1774,
the “Declarations and Resolves of the First Continental
Congress” called for non-importation of British goods, and became
a catalyst for the American Revolutionary War (1775–1784). The
resulting independence for the United States allowed trade a free rein,
and it flourished.
The westward expansion of the United States exposed a wealth of natural
resources and an increased production in agricultural goods. The inland
transportation infrastructure of roads, railroads, canals, and rivers
connected the early western settlers with the rest of the nation, and
enabled goods to move from the west back to more populated areas in the
east and onto other parts of the world. The River and Harbor
(Appropriations) Act of 1876 established federal funding of waterways to
promote national commerce but not to benefit any particular state nor to
allow waterway tolls.
Twentieth and Twenty-First Centuries
Increased levels of world trade resulted from the economic growth
occurring since the end of World War II in 1945. The United States was
in the position to take advantage of new trading opportunities as new
world markets opened. Developing countries demanded capital goods,
agricultural products, consumer goods, and commercial services, which
the United States could provide. As these nations produced goods for
export, the United States became a market for these goods.
A significant factor in the opening of the inland waterway system (and
the resultant world trade superiority of the United States) was the
advances in ship technology and the application of steam power to ships
that traveled the extensive water network. Larger and faster ships
emerged from the advances in ship and engine design and improvements in
Methods of cargo handling evolved to keep pace with the larger vessel
sizes. The introduction of palletization and roll-on/roll-off cargoes
enabled vessels to be loaded and unloaded in less time. The emergence of
containerization in the late 1950s dramatically affected the shipping
industry and port infrastructure. The increasing size of containerized
cargo vessels became a driving force in the demand for expanded ports
and improved facilities.
Importance to Foreign Trade.
Transporting goods with foreign trading partners can be accomplished by
road, water, rail, or air. However, for the
Modern ferries, cruise ships, and many types of recreational boats
carry passengers for purposes ranging from daily business commuting
to fishing to sightseeing. The ferry system in Halifax, Nova Scotia
(Canada) exemplifies the importance of waterways for transportation.
majority of foreign trading partners, the only options for
transportation are water or air. Water-based transportation is generally
the most costeffective mode for the majority of internationally traded
About 95 percent of U.S. foreign trade passes through its port system.
Ports function as the transfer point between land and water
transportation of cargo.
For vessels to transport the foreign traded cargo, they must be able to
access the ports through established channels. The channels provide
adequate water depths for the vessels and navigational aids.
Today’s Global Trade.
Today the world economy has become globalized. The economic system is
changing from one with distinct local and national markets, separated by
trade barriers, distance, time, and culture, to one that is increasingly
converging and integrating into a global economy.
According to the National Oceanic and Atmospheric Administration (NOAA),
the United States was the world’s leading trader in 1998,
accounting for about one billion tons of ocean-bound trade (about 20
percent of the world’s total ocean-bound trade) out of about 2.4
billion tons of total foreign trade. In 2000, according to the U.S.
Department of Transportation, approximately $736 billion of goods (about
40 percent of the total U.S. foreign trade by dollar amount) were
shipped via ocean vessels and passed through U.S. ports. By 2020,
international trade is estimated to more than double (by weight) within
the United States, with the majority of this trade projected to move via
Marine Transportation System.
According to the Department of Transportation, when cargo is transported
by water within the United States, 95 percent of the time it involves
the Marine Transportation System (MTS). This comprehensive system
resulted from years of water transport development involving such U.S.
organizations as the Coast Guard, Maritime Administration, Army Corps of
Engineers, NOAA, and Environmental Protection Agency.
The U.S. Marine Transportation System moves people and goods via
coastal and inland waterways. The diversity of the system’s
users is illustrated in this photograph of the Port of Tacoma,
Washington, where a sea kayaker shares the water with a container
vessel. (Container cranes and Mount Rainier are visible in the
The MTS is a complex and diverse national network of waterways, ports,
and intermodal landside connections that allows various modes of
water-based transportation. The system includes: navigable waterways
(such as the Great Lakes-St. Lawrence Seaway); publicly and privately
owned commerce-carrying vessels; over 3,500 bulk oil transfer
facilities; more than 350 ports located at approximately 4,000 marine
terminals; about 40,000 kilometers of navigable channels; more than 235
locks and dams at over 190 locations; shipyards; rail yards; vessel
repair facilities, over 10,000 recreational marinas; and a trained labor
staff that operates and maintains the entire infrastructure. Users of
the waterway system each year include 70,000 port calls for commercial
vessels, 110,000 fishing vessels, and 20 million recreational vessels.
International Maritime Fleets and Law
Many nations around the world have built up their fleets to become very
profitable. Since World War II, the size of the U.S. flag merchant fleet
has declined, partly due to improved technologies and partly due to
foreign competition among fleets. But while this number of ships has
declined, the productivity has greatly increased. Since 1970, these
fewer ships carry 42 percent more cargo. However, the U.S. fleet
accounts for less than 5 percent of all commercial foreign trade by
weight. Data from the U.S. Army Corps of Engineers and the Maritime
Administration indicate the following composition and carrying capacity
of the U.S.-flag fleet in 2000:
: 1,265 Passenger: 368,000 passengers
Dry Bulk: 10 Dry Bulk: 2,124,000 metric tons
Dry Cargo/Offshore Support: Dry Cargo: 47,253,000 metric tons 2,910
Tanker: 173 Tanker: 19,172,000 metric tons
Vehicular/Railroad Car Ferry: Railroad/Car Float: 89,000 metric 229 tons
Dredge: 570 Other
: 1,072,000 metric tons
: 45 Total: 72,078,000 metric tons/
Includes ferries and day excursion vessels
Includes certain general cargo, roll-on/roll-off, multipurpose, LASH
(Lighter Aboard Ship) vessels, and deck barges
All ships must be registered to one of the world’s nations so
that responsibility for violations of international laws and conventions
may be assigned. This causes many shipping companies to shop around for
nations that give them the best values on taxes, wages, and legal
Liberia has the largest shipping fleet in the world. Relatively smaller
countries like the Bahamas, Honduras, the Marshall Islands, Panama, and
Vanuatu have large fleets as well. The United Nation’s
International Maritime Organization (IMO) is responsible for improving
the safety of international shipping, preventing marine pollution, and
facilitating international maritime traffic. The Department of
Transportation has the overall lead on all maritime issues for the
United States, and works with the IMO on these issues.
Economics, National Security, and the Environment
The United States dependence on seas and waterways has been vital to its
economic success and national security. The pool of skilled labor
working on U.S. flag vessels is also a national security asset. This
workforce is relied upon to meet surges in shipping needs in the advent
of emergencies. The merchant marine has played a historical role in
military conflicts. In 1996, the Maritime Security Act established the
maritime security program to support a fleet of U.S. commercial vessels
with American crews to support the military and economic security of the
country; approximately 47 vessels participate in this program.
The inland waterways are also a national security asset. The 1920 Jones
Act required domestic waterborne commerce to be transported in vessels
built in the United States, documented under U.S. laws, and owned by
U.S. citizens. The Jones Act covers over 42,000 commercial vessels,
124,000 jobs, and $15 billion in economic activity. Many other countries
have similar laws restricting foreign access to domestic trade shipped
The MTS is also vital to national security. The ability to rapidly
deploy troops and materials worldwide is critical to the
country’s defense. The Voluntary Intermodal Sealift Agreement
(VISA) is a standby agreement intended to make commercial, intermodal
dry cargo capacity and supporting infrastructure available to meet
contingency deployment needs of the Department of Defense. Since World
War II, approximately 95 percent of all military equipment and material
sent to combat and crisis areas was ship cargo transported by ocean
vessels. For example, during the Persian Gulf War (1990–1991),
nearly all domestic supplies intended for U.S. military forces traveled
Marine transportation is an important use of the ocean. Increased
demands will be placed on U.S. ports and waterways as domestic and
international trade continues to expand. These increases in the use of
waterways and port facilities must be achieved while still protecting
human health and the environment.
Bauer, K. Jack.
A Maritime History of the United States: The Role of America’s
Seas and Waterways.
Columbia, SC: University of South Carolina Press, 1988.
Hershman, Marc J.
Urban Ports and Harbors Management.
New York: Taylor & Francis, 1988.
Hill, Forest G.
Roads, Rails, and Waterways: The Army Engineers and Early
Norman, OK: University of Oklahoma Press, 1957.
Kendall, Lane C.
The Business of Shipping.
Centreville, MD: Cornell Maritime Press, 1979.
Marcus, Henry et al.
Federal Port Policy in the United States.
Cambridge, MA: The MIT Press, 1976.
See “Oil Spills: Impact on the Ocean” and “Ports
and Harbors” for photographs of busy U.S. ports.