He was directed to cruise "from Cape Henry to Nantucket," to "defend this extent of coast against the depredations of the vessels sailing under authority or pretence of authority of the French Republic," and to "afford all possible protection to the vessels of the United States coming on or going off the coast," in conjunction with Captain Dale. Captain Barry was authorized "to subdue, seize and take any armed French vessel which should be found within the jurisdictional limits of the United States or elsewhere on the high seas, with apparel, guns and appurtenances." On July 11, 1798, Secretary Stoddert notified Barry that information was received that "the French have considerable force in the West Indies" and that "it is thought that a small squadron under the command of an officer of your intelligence, experience and bravery might render essential service and animate your country to enterprise by picking up a number of prizes in the short cruise of these islands."
So Barry was directed to take the "Delaware," Captain Stephen Decatur; the "Herald," Captain Sever, and a revenue cutter of 14 guns from Boston "and to proceed to the West Indies and so dispose of the vessels as to afford the greatest chance of falling in with French armed vessels," to "look into St. John's, the principal harbor of Porto Rico and after two or three days' cruising, return to the continent."
"The object of the enterprise," said the Secretary, "is to do as much injury to the armed vessels of France and to make as many captures as possible." He closed saying, "It is scarcely necessary for me, in writing to a brave man who values his own country, its government and its laws, to suggest the usefulness of inculcating upon those under his command the propriety of preserving in their language and conduct the same respect which he himself feels for those constitutions and those characters which deserve the respect of all. It is time we should establish an American character. Let that character be a love of country and a jealousy of its honor. This idea comprehends everything that ought to be impressed upon the minds of all our citizens, but more especially of those citizens who are seamen and soldiers."