_The Seven-Days Battles_.--The very morning McClellan came to this decision, and ere the flank movement had commenced, Lee, massing his strength on his left, fell upon the Union right at _Mechanicsville_ (June 26). Having repulsed this attack, at dawn the troops retired to _Gaines's Mill_, where by the most desperate exertions Porter held the bridges across the Chickahominy until night, and then, burning them, withdrew to the south bank. That night (June 28) Lee detected McClellan's movement, and instantly started columns along the roads that intersected the line of retreat. Magruder struck the Federal flank (June 29) at _Savage's Station_. The Union troops maintained their position till night, and then continued the movement. Longstreet and Hill encountered the line of march as it was passing _Frazier's Farm_ (June 30), but could not break it. During the darkness, the Union troops, worn out by the constant marching or fighting and the terrible heat and dust, collected at _Malvern_. On an elevated plateau rising in the form of an amphitheatre, on whose sloping sides were arranged tier upon tier of batteries, with gunboats protecting the left, the broken fragments of the splendid Army of the Potomac made their last stand (July 1). Here Lee received so bloody a check that he pressed the pursuit no further. The Union troops retired undisturbed to Harrison's Landing. _The Effect_ of this campaign was a triumph for the Confederates. The Union retreat had been conducted with skill, the troops had shown great bravery and steadiness, the repulse at Malvern was decided, and Lee had lost probably twenty thousand men; yet the siege of Richmond had been raised, ten thousand prisoners captured, immense stores taken or destroyed, and the Union army was now cooped up on James Kiver, under the protection of the gunboats. The discouragement at the North was as great as after the battle of Bull Run. Lincoln called for a levy of three hundred thousand troops. CAMPAIGN AGAINST POPE.--Richmond being relieved from present peril, Lee threatened to march his victorious army against Washington. General Pope, who commanded the troops for the defence of that city, was stationed at the Rapidan. General McClellan was directed to transfer his army to Acquia Creek (see map), and put it under the command of General Pope. Lee, now relieved from all fear for Richmond, immediately massed his troops against Pope to crush him before the Army of the Potomac could arrive. [Footnote: In the meantime Jackson attacked Banks at _Cedar Mountain_ (August 9) and defeated him after a bloody battle, but, unable to maintain his position, fell back on Lee's advancing army. Pope, seeing the fearful odds against which he was to contend, took post behind the Rappahannock.]