Last year, in my scintillating three-part essay on the Embargo of 1807-09, I wrote dismissively of American commerce with the Danish port of Tonning (or "Tonningen," as my source spelled it), asserting that American merchants falsely listed it as their destination in order to secure clearance for voyages to more lucrative ports in Britain or French-occupied Europe. I have since learned that there was actually quite a bit of American trade with Tonning between 1808 and 1810: 100 ships from the United States dropped anchor there in 1809, drawn there by Tonning's proximity to the French-occupied port of Hamburg. Between the end of the Revolutionary War and the start of the Napoleonic Wars, American merchants had developed a strong presence in Hamburg, where they sold American cotton, tobacco, and rice, as well as Caribbean sugar and tobacco. Hamburg was attractive to U.S. merchants partly because of its population of English-speaking traders - Napoleon would derisively call it "cette ville Anglaise" - and partly because of its accessibility, via the Elbe and associated canals, to the rest of Germany. In 1804, however, a British blockade closed the Elbe to unlicensed shipping, and three years later French occupation authorities began harassing American merchants in the city, suspecting they were actually British smugglers violating the Berlin and Milan decrees. Eager to continue trading with Germany, American merchants began looking for holes in Napoleon's Continental System, and in 1808 they found one in Tonning, located about 25 miles north of the Elbe and 60 miles from Hamburg. By the next year Americans were smuggling sugar and tobacco across the Danish border from Tonning to Hamburg, though they had to pay increasingly heavy bribes to French customs officials to do so. In 1810 a French crackdown on American goods and English-speaking traders in northern German ports effectively closed this "loophole." (See Sam Mustafa, Merchants and Migrations: Germans and Americans in Connection, 1776-1835 [Aldershot, UK, 2001], 119, 126, 206-09; J.J. Oddy, European Commerce, Shewing New and Secure Channels of Trade with the Continent of Europe [2 vols., Philadelphia, 1807] 2:139, 142.)
In any event, I won't be running down small nineteenth-century Danish ports again any time soon.