Moreover, the States were jealous of each other, possessing no true community of interest, and each seeking advantage at the expense of its neighbors.

They were already beginning to adopt among themselves the very tactics of harassing and crippling navigation laws which caused the protest against Great Britain.
This "Critical Period of American History," as Professor Fiske calls it, was indeed a critical period for American shipping.
The new government, formed under the Constitution, was prompt to recognize the demands of the shipping interests upon the country.

In the very first measure adopted by Congress steps were taken to encourage American shipping by differential duties levied on goods imported in American and foreign vessels.

Moreover, in the tonnage duties imposed by Congress an advantage of almost 50 per cent.

was given ships built in the United States and owned abroad.