The Intracoastal Waterway (ICW) is a inland waterway along the Atlantic and Gulf of Mexico coasts of the United States, running from Massachusetts southward along the Atlantic Seaboard and around the southern tip of Florida, then following the Gulf Coast to Brownsville, Texas. Some sections of the waterway consist of natural inlets, saltwater rivers, bays, and sounds, while others are artificial canals. It provides a navigable route along its length without many of the hazards of travel on the open sea.
Since the coastline represented the national border, and commerce of the time was chiefly by water, the fledgling United States government established a degree of national control over it. Inland transportation to supply the coasting trade at the time was less known and virtually undeveloped, but when new lands and their favorable river systems were added with the Northwest Territory in 1787, the Northwest Ordinance established a radically new and free national policy for their development and transportation use.
Over time, internal improvements of natural coastal and inland waterways would develop into the Great Loop, which allows for waterborne circumnavigation of the eastern continental United States, using minimal ocean travel, with the Intracoastal Waterway providing its eastern end. In 1808, the first federal government report on existing, possible, and likely avenues of transportation improvement was presented; it included much of the distance where the ICW now traverses the Atlantic coast. At the request of the Senate, Treasury Secretary Albert Gallatin presented an overall plan for future transportation developments of national importance and scope. Along with inland east–west improvements, Gallatin's north–south improvements included the following:The map of the United States will show that they possess a tide water inland navigation, secure from storms and enemies, and which, from Massachusetts to the southern extremity of Georgia, is principally, if not solely, interrupted by four necks of land.