The first visitation of the yellow fever was in 1769. Since that time it has continued to be almost an annual scourge. It was introduced into this continent, in the above named year, _by a British vessel_, from the coast of Africa, _with a cargo of slaves_. In addition to this affliction, (the yellow fever above alluded to,) the colony was, during the year 1769, transferred to Spain, and the capital was taken possession of by O'Reilly, with a show of military power, and an individual disposition to oppress, that brought equal disgrace upon himself, and upon the government that commissioned him. The commerce of this city suffered very much from the restrictive colonial system of Spain. This, however, was removed in 1778, (a year memorable for a fire that burnt nine hundred houses at one time) and, in 1782, the mercantile interest of the place was benefited by still further extended privileges of trade. The census of 1785 gives to the city a population of 4,780, exclusive of the settlements in the immediate vicinity. In consequence of the commercial advantages above alluded to, a number of merchants from France established themselves here, and British trading vessels navigated the Mississippi. They were a species of marine pedlars, stopping to trade at any house, by making fast to a tree, and receiving in payment for merchandise, whatever the planter had to spare, or giving him long credits. The Americans, at that time, commenced the establishment of that trade from the west to New Orleans, which has been steadily increasing ever since. The idea of this traffic was first conceived by General Wilkinson. A lucrative business was also conducted by the Philadelphians, which the colonial authorities winked at for a while; but the Spanish minister, finding that he did not participate in the profits of it, as the Americans refused to comply with his hints to consign to his friends, put a stop to it. He procured a list of the names of the vessels, severely reprimanded the intendant, Navarro, and so worked upon his fears that he began to prosecute all infringements of the revenue laws, seizing the vessels, confiscating the goods and imprisoning the owners, captains and crews. The venal minister, perceiving that he had rendered himself extremely unpopular by his intermeddling with the commerce between Philadelphia and New Orleans, finally released all the individuals he had imprisoned, restoring the confiscated property, and discontinuing any further interference. The trade immediately received a new impulse and was greatly increased. General Wilkinson at the same time obtained permission to send one or more launches loaded with tobacco, from Kentucky. Soon after, many Americans availed themselves of a privilege which was granted, of settling in the country.