The particulars of the conquest of Upper California, as well as the suppression of the insurrections, we have already given in substance as they are in the despatches of General Kearny and Commodore Stockton. But we have said nothing of the transactions in the Peninsula, as that afterwards was surrendered to Mexico. All that is interesting in the conquest of Lower California, will be found in the following despatches from the commander of the New York regiment of volunteers, which with a number of marines were the only troops employed in that quarter. We premise, that, after the United States marines had taken San José, the natives rose, and they were reduced to the necessity of taking refuge in an old fort, or _cuartel_, in the town. BARRACKS, LOWER CALIFORNIA, _San Jose, February 20, 1848_. SIR: I continue my report from the 22d ultimo, from which time my force consisted of twenty-seven marines and fifteen seamen, of whom five were on the sick report, besides some twenty volunteers, Californians, who at least served to swell the numbers. From that date the enemy were continually in sight of us, intercepting all communication with the interior, and driving off all the cattle from the neighborhood. A party of our men who went out to endeavor to obtain cattle, were driven in and narrowly escaped being cut off. We succeeded in obtaining a few cows, however, which were very necessary to us in the reduced state of our provisions, as, in addition to our garrison, we were obliged, in humanity, to sustain some fifty women and children of the poor, who sought our protection in the greatest distress. I found it necessary, as soon as our fresh beef was consumed, to put all hands on half allowance of salt provisions. We had no bread. On the 4th of February, the enemy closed around us more, and commenced firing upon all who showed themselves at our port-holes, or above the parapets. On the morning of the 6th the enemy appeared to be a little scattered, a considerable force being seen riding about some distance from the town, and at the same time a strong party of them posted at the lower end of the street were keeping up an annoying fire upon us. I judged this a favorable opportunity to make a sortie upon them, and taking twenty-five men with me, closed with them and dislodged them, driving them into the hills without the loss of a man on our part, and returned to the cuartel. On the morning of the 7th it was reported to me that the enemy had broken into the houses on the main street, and there was some property exposed which might be secured. I took a party of men and went down and brought up a number of articles belonging to the Californians, who were in the cuartel; some distant firing took place, but no injury was sustained. On the same day, hearing there were some stores of rice and tobacco in a house some three hundred yards down the main street, I determined upon an effort to obtain them, and sallied out with thirty men: these were