In 1826, he revisited the United States, and hearing of the war between Brazil and the Republic of Buenos Ayres, sailed from Boston in the brig Hitty, of Portsmouth, with a determination, as he states, of trying his fortune in defence of a republican government. Upon his arrival he made himself known to Admiral Brown, and communicated his desire to join their navy. The admiral accompanied him to the Governor, and a Lieutenant’s commission being given him, he joined a ship of 34 guns, called the ‘Twenty Fifth of May.’ “Here,” says Gibbs, “I found Lieutenant Dodge, an old acquaintance, and a number of other persons with whom I had sailed. When the Governor gave me the commission he told me they wanted no cowards in their navy, to which I replied that I thought he would have no apprehension of my cowardice or skill when he became acquainted with me. He thanked me, and said he hoped he should not be deceived; upon which we drank to his health and to the success of the Republic. He then presented me with a sword, and told me to wear that as my companion through the doubtful struggle in which the republic was engaged. I told him I never would disgrace it, so long as I had a nerve in my arm. I remained on board the ship in the capacity of 5th Lieutenant, for about four months, during which time we had a number of skirmishes with the enemy. Having succeeded in gaining the confidence of Admiral Brown, he put me in command of a privateer schooner, mounting two long 24 pounders and 46 men. I sailed from Buenos Ayres, made two good cruises, and returned safely to port. I then bought one half of a new Baltimore schooner, and sailed again, but was captured seven days out, and carried into Rio Janeiro, where the Brazilians paid me my change. I remained there until peace took place, then returned to Buenos Ayres, and thence to New York.