The Navy Yard and forts in the harbor of Pensacola, from their extent and importance, were particularly the objects of insurgent ambition. General Bragg and his counsellors had so adroitly arranged their plans that it was confidently expected that the government forts, buildings and property would fall into their peaceable occupation. On the 12th of January, the navy yard and barracks, together with Fort Barrancas, fell into their possession, and shortly afterwards Fort McRae met with the same fate; but Lieutenant Slemmer, the United States officer in command of the forts of Pensacola harbor, courageously threw his small force of eighty-two men into Fort Pickens, and had thus far held at bay the large army of insurgents who were preparing to attack him. The harbor of Pensacola is probably the largest and finest on the whole coast of the Mexican Gulf. The bay is six miles wide and about twelve long. The Warrington navy yard was seven miles by land from Pensacola and six miles and three-quarters by water. About a mile from the navy yard, west, stood Fort Barrancas, and a mile farther Fort McRae, which commands the bar. Opposite Fort McRae was Fort Pickens, the channel running between them. Near Fort Pickens was a redoubt. On the opposite side of Pensacola, across the bay, Santa Rosa island extends several miles to the bar, at the extremity of which is Fort Pickens. A vessel coming into the harbor must necessarily pass between Fort Pickens and Fort McRae, and in close proximity to Barrancas. Fort Pickens is a bastioned work of the first class, built of New York granite; its walls forty-five feet in height and twelve in thickness. It is embrasured for two tiers of guns, placed under bomb-proof casemates, besides having one tier _en barbette_. The work was commenced in 1848 and finished in 1853, at a cost of nearly one million dollars. Its war complement of soldiers is 1,260. Its full armament consists of 210 guns, howitzers, and mortars, of all calibres. Simultaneous with the determination to reinforce Fort Sumter, the government resolved to send relief to Fort Pickens, which was then threatened by a force of 7,000 men under General Bragg, strongly entrenched, and occupying the other forts in the harbor. A fleet of six United States vessels lay in the harbor, and they had been notified by General Bragg that he would immediately open fire upon them and Fort Pickens also, should they attempt to reinforce the garrison.