Wasn’t allowed to use foreign ships.
Dead wrong. A British flagged ship could take on a full load of cotton in Charleston and sail to Liverpool England without any problem. A French flagged ship could take on a full load of tobacco in Norfolk and sail to LaHarve France. No U.S. law prevented Southerners from shipping anything in a foreign flagged ship from a Southern port to a European port.
The 1814 Navigation act did prevent foreign flagged ships in intercoastal trade in the United States.
Rust Bucket was kind enough to find me a link to the person I spoke of who had more insight on this point. It was a system of control, and the Navigation Act of 1817 was a major component of it, but not the only component.
For many weeks I have seen interesting comments here that are truly misleading. My direct and indirect family ties date to the mid 1700s. They were engaged in ship building and finance. Some here would recognize names.For decades following the use of the gin, the planters controlled their own cotton industry. Southern cotton was shipped directly from southern ports by its owners or brokers to the textile mills of England or Lowell. During the three decade period before 1860, with our politicians action, our shippers forced the cotton trade to into our ships. First, the Navigation Acts authored by Congress at the turn of the century had established protectionist laws favoring our shipping over foreign interests. Southrons were required by law to either use our ships for their shipping, or pay to the Treasury compensation for their use of foreign ships. Foreign ships were prohibited by law from engaging in coastal trade between US harbors. Federal law cut them out. The laws highly discouraged southern boat builders from becoming involved in the shipping business by prohibiting their purchase of finished ships from overseas. To our benefit and profit and with the aid of Federal laws, we came to dominate the carrying trade of the South. As our trade in cotton increased, our financial people saw opportunity and began sending agents south to purchase all the cotton they could, and ship it on our packet ships to England and Europe. Direct purchase of cotton by the “factors” enabled the Southern growers to quickly turn a profit instead of waiting months for the cotton to be sold, and the money to return to them. But this benefit also cut their profits. Business was business and our men in Washington ensured that we would have most of it.