Commander S. P. Lee, with the advance of the squadron, arrived near Vicksburg, May 18, and in reply to his demand for surrender, received a defiant refusal. Flag-Officer Farragut arrived a few days afterwards, accompanied by a column of troops under General Williams. Additional naval forces soon afterwards arrived, including Commodore Porter’s mortar fleet, which had done much effective service in the reduction of Forts Jackson and St. Philip, at the mouths of the river. Porter opened the bombardment on the night of June 26–27, directing fire partly against the town and partly against some formidable batteries on the heights. On the morning of the 27th, the Owasco, Lieutenant Guest, ran up abreast of the town and threw in some incendiary shells, which failed to explode. At three o’clock on the morning of the 28th the squadron made a move to pass the batteries, the mortar fleet supporting them as at the battle of Forts Jackson and St. Philip. The Hartford and several other vessels succeeded in passing the range of batteries, which extended full three miles, and did this too in the face of a strong current, but as there was not a sufficient land force to cooperate in the attack, no substantial benefit resulted from the movement. The enemy were several times driven from their batteries, but returned to their guns as soon as the ships had passed. Forming a junction with the western gunboat flotilla of Flag-Officer C. H. Davis, Farragut concerted with that officer and General Williams an expedition up the Yazoo River, consisting of the gunboats Carondelet and Tyler, and the ram Queen of the West, strengthened by sharpshooters from the army. They started on the morning of July 15, and near the mouth of the river encountered the Confederate ram Arkansas. A severe fight ensued, in which both the Carondelet and the Tyler were partially disabled, and the Arkansas then entered the Mississippi and passing boldly through the surprised fleets of Farragut and Davis, took refuge under the guns of Vicksburg. Farragut now determined to repass the batteries for the double purpose of supporting the rest of his squadron and destroying the Arkansas in passing; to assist in which Flag-Officer Davis added to his force the ram Sumter, Lieutenant Commanding Erben. Toward evening, Davis opened a bombardment, for the purpose of covering the movement, and Captain Farragut succeeded in getting below Vicksburg again with little loss of life, but his designs against the Arkansas were defeated by the darkness of the night.