On March 20, 1836, the brig Pocket, a registered United States merchant vessel from Boston, made preparations to sail from New Orleans to the port of Matamoros, Tamaulipas. While in port, the Pocket was contracted by M. de Lizardi and Company, a mercantile house under purchase instructions from Rubio and Company, a worldwide general agent for Antonio López de Santa Anna, to ship and deliver war contraband and other provisions to Matamoros to assist Santa Anna's reconquest of Texas. In addition, Lizardi provided Capt. Elijah Howes, master of the Pocket, with a signal pennant described as being white with a black cross, a sign that the provisions aboard the Pocket were to support Santa Anna's operation. Furthermore, the Pocket had aboard as passengers several well-known Mexican naval officers as well as United States citizens.
On April 3, 1836, somewhere near the mouth of the Rio Grande, the Pocket encountered the Texan armed schooner Invincible, mastered by Jeremiah Brown. Brown was previously informed about the plot to ship provisions to Santa Anna under a special identification signal by William Bryan, general agent for Texas, while Brown was awaiting departure for the Texas coast in February and March 1836. Upon noticing the signal pennant, Brown decided to board the Pocket. Once aboard, he compared the cargo with the manifest and immediately discovered that several items there were not listed, especially arms and ammunition. Brown found a detailed map of the coastline of Texas and military dispatches written in Spanish. He also recognized one of the Mexican naval officers. Based on this evidence, he assigned a prize crew to sail the Pocket to Galveston Island, where all was turned over to James Morgan, commandant.
Brown escorted the Pocket to Galveston and disposed of his prize because the Invincible was scheduled to be refitted at New Orleans. While the Invincible was in that port, news of the capture and return of most of the crew and passengers inflamed the situation. Bad press by New Orleans publications incited the local merchants into a united front with the insurance carriers to do something to protect their commerce in the Gulf of Mexico. No such protection ensued, however, their fierce lobbying forced the hand of local federal officials, who requested Commodore A. J. Dallas, United States Gulf of Mexico squadron commander, to arrest the crew of the Invincible on a charge of piracy.
On May 1, 1836, the crew was arrested. After a hearing they were released because evidence of piracy could not be substantiated. Later Jeremiah Brown made a statement to a local port official that again caused consternation among merchants and insurance carriers. The crew would have been arrested a second time, but William Bryan, in cooperation with the Toby and Brother Company, temporarily appeased those individuals by purchasing the Pocket for $35,000 and settling some additional claims.
However, the Pocket affair was not settled by this gesture of good faith. Shortly thereafter, the insurance carrier for the cargo of the Pocket filed a civil action to recover the money it had paid to M. de Lizardi and Company. Jeremiah Brown was again arrested and held for $9,000 bond, which William Bryan and Toby and Brother paid to secure his release. This civil action lingered on the court dockets until 1840, and a final disposition of the suit has not been discovered. Several claimants aboard the Pocket clamored for redress. Since Texas did nothing regarding a negotiated settlement, the claimants asked the United States government to intercede. Finally, after some controversy, a convention of indemnity was agreed upon between the United States and Texas. The Pocket affair officially ended with the signing of this document on April 11, 1838.
The Pocket incident, coupled with earlier seizures of other American merchant vessels, forced Texas to recognize the rights of other nations upon the seas. Because of the Pocket affair Texas had to announce formally a blockade of Mexican ports. Also, Texas established a district court with admiralty jurisdiction to adjudicate prize vessels, a move that had not been contemplated before the capture of the Pocket.