单项选择题

TEXT C
It is said that George Washington was one of the first to realize how important the building of canals would be to the nation’s development. In fact, before he became President, he headed the first company in the United States to build a canal which was to connect the Ohio and Potomac rivers. It was never completed, but it showed the nation the feasibility of canals. As the country expanded westward, settlers in western New York, Pennsylvania, and Ohio needed a means to ship goods. Canals linking natural waterways seemed to offer an effective solution.
In 1791 engineers commissioned by the state of New York investigated the possibility of a canal between Albany on the Hudson River and Buffalo on Lake Erie, which would link the Great Lakes area with the Atlantic seacoast. It would avoid the mountains that served as a barrier to canals from the Delaware and Potomac rivers.
The first attempt to dig the canal, to be called the Erie Canal, was made by private companies, but only a comparatively small portion was built before the project was halted for lack of funds. The cost of the project was an estimated five million dollars, an enormous amount for those days. There was some on-again-off-again Federal funding, but the War of 1812 put an end to this. In 1817 DeWitt Clinton was elected Governor of New York and persuaded the state to finance and build the canal. It was completed in 1825, costing two million dollars more than expected.
The canal rapidly lived up to its sponsors’ faith, quickly paying for itself through tolls. It was far more economical than any other form of transportation at the time. It permitted trade between the Great Lake region and East Coast, robbing the Mississippi River of much of its traffic. It allowed New York to supplant Boston, Philadelphia, and other Eastern cities as the chief center of both domestic and foreign commerce. Cities sprang up along the canal. It also contributed in a number of ways to the North’s victory over the South in the Civil War.
An expansion of the canal was planned in 1849. Increased traffic would undoubtedly have warranted its construction had it not been for the development of the railroads.
According to the passage, the Erie Canal connected the______.