The battle of Bull Run, when General Joseph E. Johnston, commanding the Confederates, defeated General McDowell with serious loss, and sent the Union army in disorderly retreat toward Washington, taught the Northern people that the war was not a parade, and that the overthrow of the Confederacy would tax all the energies of the loyal States. Fortunately, General George H. Thomas won an important victory for the Union at Mill Spring, Kentucky, in January, 1862, and the capture of Fort Henry and Fort Donelson, in the following month, by General Ulysses S. Grant, aided by Commodore Foote and his gunboats, tended to efface the depression caused by defeat in Virginia. General Grant's reply to the Confederate General Buckner, when the latter wished to make terms for the surrender of Fort Donelson, was on every tongue in the North. "I have no terms but unconditional surrender. I propose to move immediately upon your works," was a message that spoke the man. Nearly sixteen thousand prisoners were captured. They belonged mostly to the working classes of Missouri, Tennessee and Arkansas. * * * John Ericsson's Monitor, in March, 1862, sent a thrill of relief and joy through the North by its wonderful victory over the Merrimac. The Confederates cut down a United States frigate at the Norfolk navy yard, and transformed it into an ironclad ram, with a powerful beak. This monster they sent against the Union fleet of wooden warships in Hampton Roads. Broadsides had no effect on the Merrimac. The floating fortress attacked the Cumberland, ramming that vessel, and breaking a great hole in its side. The Cumberland sank with all on board. The Congress was driven aground and compelled to surrender. Then the monster rested for the night, intending to continue its mission of destruction on the morrow. It seemed that not only the Union fleet, but the ports and commerce of the North would be at the mercy of this novel and terrible engine of destruction. The telegraph carried the news everywhere, and in dread and anxiety the people awaited the fate of another day. When morning came at Hampton Roads a small nondescript vessel, looking like an oval raft with a turret, interposed between the Merrimac and its prey. It was the Monitor, the invention of Captain John Ericsson, and it had arrived during the night of March 8. The Monitor had been constructed at Greenpoint, Long Island, and was towed to Hampton Roads by steamers. Her turret was a revolving, bomb-proof fort, in which were mounted two 11-inch Dahlgren guns. As the turret revolved the great guns kept up a steady discharge, battering the sides of the Merrimac. The latter hurled enormous masses of iron on the Monitor, but made no impression whatever on the little craft, and the duel continued until the Merrimac gave up the fight, and ran back to shelter at Norfolk. Ericsson's praise was on every tongue. The great Swedish engineer whose sanity had been questioned