13. At first the government of the United States was disposed to defend Captain Wilkes's action. Had such a course been taken, war with Great Britain would have been inevitable. The country was saved from the peril by the diplomacy of William H. Seward, the Secretary of State. When Great Britain demanded reparation for the insult, and the liberation of the prisoners, he replied in a mild, cautious, and very able paper. It was conceded that the seizure of Mason and Slidell was not justifiable according to the law of nations. An apology was made for the wrong done; the Confederate ambassadors were liberated, put on board a vessel, and sent to their destination. So ended the first year of the civil war. CHAPTER XLVII. CAMPAIGNS OF 1862. The Federal forces now numbered about four hundred and fifty thousand men. Of these nearly two hundred thousand, under General McClellan, were encamped near Washington. Another army, commanded by General Buell, was stationed at Louisville, Kentucky. 2. At the beginning of the year the capture of Fort Henry on the Tennessee and Fort Donelson, on the Cumberland, was planned by General Halleck. Commodore Foote was sent up the Tennessee with a fleet of gunboats, and General Grant was ordered to move forward against Fort Henry. Before the land-forces reached that place, the flotilla compelled the evacuation of the fort, the Confederates escaping to Donelson. [Sidenote: Fort Donelson.] 3. The Federal gunboats now dropped down the Tennessee and then ascended the Cumberland. Grant pressed on from Fort Henry, and began the siege of Fort Donelson. The defences were manned by ten thousand Confederates, under General Buckner. Grant's force numbered nearly thirty thousand. On the 16th of February Buckner was obliged to surrender. His army became prisoners of war, and all the magazines, stores, and guns of the fort fell into the hands of the Federals. [Sidenote: Battle of Shiloh.] 4. General Grant now ascended the Tennessee to Pittsburg Landing. A camp was established at Shiloh Church, near the river; and here, on the 6th of April, the Union army was attacked by the Confederates, led by Generals Albert S. Johnston and Beauregard. All day long the battle raged with great slaughter on both sides. Night fell on the scene with the conflict undecided; but in the crisis General Buell arrived with strong reinforcements. In the morning General Grant assumed the offensive. General Johnston had been killed, and Beauregard was obliged to retreat to Corinth. The losses in killed, wounded, and missing were more than ten thousand on each side. [Sidenote: Island Number Ten.]