"Domestic waterborne shipping in the United States moves 14% of the national cargo tonnage for less than 2% of the freight bill, provides an estimated 124,000 direct jobs, generates $10 billion in annual freight revenue, and provides $300 million and $55 million in federal and state tax revenue respectively. Domestic waterborne transportation is safe, reliable, efficient and an established mainstay of America's national transport system. (1) The total volume of domestic water trade is immense. In 1996, the volume of cargo moved between U.S. Ports by the domestic fleet exceeded one billion tons. (2) The total direct economic activity associated with the domestic trade is approximately $10 billion per year, which includes more than $4 billion in direct wages paid to vessel crews and shore side managers. To encourage a strong U.S. merchant marine for both national defense and economic security, the nation's domestic waterborne commerce is reserved for vessels built in the United States, owned and crewed by American citizens, and registered under the American flag. U.S. laws governing the domestic transportation of passengers and cargo by water are generally known as the Jones Act, named after Senator Wesley Jones (R-WA) the sponsor of the Merchant Marine Act of 1920. The Jones Act continues to be the foundation for America's domestic shipping policy. This pamphlet describes America's domestic shipping trades and the essential services they provide for a healthy, growing economy."
U.S. Department of Transportation: Maritime Administration: http://www.marad.dot.gov/index.html