While the costs of violations were steep, the law did little to stem the trade. Owners could choose from a variety of subterfuges to disguise the purpose of voyages. Using sympathetic customs officials, forging ship’s papers, crewing vessels with Americans but sailing under foreign flags, and selling vessels in the West Indies to avoid returning to American ports were all used at one time or another to circumvent the law.
The only enforcement mechanism was for citizens to observe the off loading of slaves at foreign ports — typically in the West Indies — and causing suits to be brought in the Federal Court at the vessel’s home port where, upon return, it could be seized and condemned. Unfortunately, the home ports of these vessels often proved to be unwelcome jurisdictions for such suits. Ships condemned and auctioned were often sold back to the original owners at a bargain price when no other bidders materialized, there being a tacit understanding among the locals that they should stay away. To counter this, the Federal Government authorized court clerks to bid on the government’s behalf. Brazenly, in 1799, owners of the Lucy, of Bristol R.I., arranged for the kidnapping of a customs official on the day of the auction to prevent a competing bid . It would take war with France to provide the U.S. with a different way to enforce the law — at sea.
In 1794, enforcing U.S. law by interdicting the slave trade at sea was not an option. The Unites States had no ocean-going Navy and a small complement of revenue cutters. As we shall see, in 1798 the French finally provided the motivation for the United States to create one for self-defense. American warships put to sea in 1798 with the primary mission of defending American merchant vessels from French privateers, but also could report any violations of the 1794 act they observed while on patrol. The Navy would forward these reports to the Treasury Department who would, in turn, alert the pertinent federal revenue authorities who could then take action when a vessel returned to its home port.
For example, in early 1799, Capt. William Bainbridge of the brig Norfolk sent a list of 5 slaving vessels to Navy Secretary Stoddert who duly passed it on to Treasury Secretary Wolcott. It’s not clear if any legal action resulted from the report however. 
The situation change significantly in May 1800, when Congress strengthened the 1794 slave trade act. It increased penalties, closed loopholes and, most important for our story, authorized “any of the commissioned vessels of the United States to seize and take any vessels employed” contrary to the Act. The legal stage was set for what was to come and the Navy immediately got to work. 
 Richard Peters Esq. ed., Public Statutes at Large of the United States of America, (Boston, Little and Brown, 1845), II:70. Available online.
 Ibid. I:348. Available online.
 Cynthia Mestad Johnson, James Dewolf and the Rhode Island Slave Trade (Charleston, SC, History Press, 2014), pp 75–82. Pertinent clips from the book are available online at Google Books (accessed April 26, 2019).
 Office of Naval Records and Library, Naval documents related to the quasi-war between the United States and France & Naval Operations From January 1800 to May 1800, Washington : U.S. G.P.O., 1938. Vol. 4, p. 426. The Norfolk had arrived in Philadelphia from Havana on April 12, 1800.
 Public Statutes, II:70.