The idea behind the Peninsular Campaign was an advancement of the Union forces into Virginia and the taking of Richmond. Under pressure from President Lincoln, McClellan started the deployment of his troops. The campaign began in April 1862 when Gen. George B. McClellan moved his force of 110,000 onto the peninsula between the York and James rivers. 
After McClellan's army defeated the Confederate forces he could move in and siege Richmond. McClellan's plan was to move his flanks in while he was backed by Union gunboats, and with the combination of both forces McClellan hoped to beat or severely weaken Richmond's defenses. Although McClellan's plan seemed to be a worthwhile investment by the government, the campaign turned out to be a major disappointment to Lincoln and his advisers. The failure was due to several faults in the plan. The huge amounts of troops caused movement to be extremely cumbersome and time consuming. McClellan also proved to be an extremely difficult officer to work with, often disobeying orders. Even with such difficulties McClellan landed his forces just southeast of Yorktown on April 1862, which he captured a month later.
Gen. Johnston, in seeing McClellan coming, moved a large quantity of his army to the security of Richmond, while sending the rest of his troops to attack McClellan. Johnston was able to stall McClellan by using several deceptive methods. One was the use of a little bit of running by his troops, who ran from site to site in order to make an impressive image for the Union soldiers. To McClellan it appeared that 
Johnston's army was five or six times larger than its actual size. Finally, Lincoln ordered McClellan to move so he did but only after asking for reinforcements. A battle broke out near Seven Pines a few miles east of Richmond, on May 31-June 1, 1862. In battle Johnston was severely wounded and Lee was given command of Johnston's army. Lee immediately planned to attack McClellan. He summoned Jackson from the Shenandoah Valley, and attacked one of McClellan's exposed flanks above the Chickahominy River.
In the Seven Days Battles (June 26-July 2,1862), Lee hurled his 85,000 men against McClellan's 100,000. Successive clashes at Beaver Dam Creek, Gaines's Mill, Savage's Station, and Glendale brought the armies to the terrible battle of Malvern Hill on July 1. Here Lee was checked, but McClellan, ordered by Washington authorities not to take the offensive with his weakened troops, retreated to the Union base at Harrison's Landing, and the campaign ended in failure. No land was gained by either side so the campaign was a draw.
J.E.B. Start's Raid, June 12-15, 1862
Lee's first move was to send Stuart off on June 12 to, basically, run a large circle around the Union soldiers to find what they could about the Union positions and their defenses. As Stuart began his circle he headed almost headed due north and then turned straight east. After a few short skirmishes with a couple units of Union soldiers, they continued on down the Peninsula. The most important information that Stuart brought back to Lee was the fact that the entire Union right flank was totally exposed without much support. This is just the news that Lee wanted to here.
The Battle of Mechanicsville, June 26,1862
The Battle of Mechanicsville was similar to that of Fair Oaks, in which Lee planned to concentrate the main section of his army on an exposed flank, in this case the right one, and use another two divisions to keep the other Union divisions busy. The main attack was to come down on Major General Fitz-John Porter's Fifth corps north of the Chickahominy River, while Magruder and Huger kept some 60,000 to 80,000 men busy south of the Chickahominy River. Longstreet, A.P. and D.H. Hill, and Jackson would attack the right flank.
In order for Lee's plan to work, two things had to occur. One, Magruder and Huger had to keep the main bulk of the army occupied with a convincing performance. Two, D.H. Hill and Jackson had to have correctly coordinated movement. The latter occurred but unfortunately communications between Jackson and D.H. Hill got scrambled and Hill had to make a solo attack on Porter. The attack was brushed back but McClellan still feared that his army was largely outnumbered and moved Porter back to Gaines' Mill.
Lee's first plan had backfired but now he was more determined than ever to crush Porter. Next he planned to pursue his attack and drive Porter south of the River.
The Battle of Gaines's Mill, June 27, 1862
On June 27, the Confederates moved into position to attack the now repositioned Porter, near Gaine's Mill. The battle finally got under way about 2:30 P.M., again without the help of Jackson. Jackson on his way there had made a wrong turn and had to backtrack several miles causing him to be more than two hours late. By the time that Jackson showed up, Porter's division had just fallen under an assault by Hood's Texas Brigade. The army then continued to pursue Porter as he headed south across the Chickahomiy. Although Lee had had superior numbers in the battle, 50,000 to 35,000, he suffered over 8,000 casualties, while the Union suffered 4,000. Between the combination of the two battles, it forced McClellan to back out of his offensive position at Richmond and head back to the James river.
The Battle of Frayser's Farm, June 30, 1862
After a short skirmish at Savages Station the two forces once again met at Frayser's Farm. Once again the Confederates were without the help of Jackson, this time because of a destroyed bridge. Huger also got stopped along the way in some thick woods. Lee's force, in the Battle of Frayser's Farm, than consisted of A.P. Hill's and Longstreet's divisions. There was a fifth force, Holmes', but he was too small of a division to do anything. All that was gained from the battle was the Federals continued retreat and some woods. The last battle of the Seven Days was yet to come.
The Battle for Malvern Hill, July 1, 1862.
That night, Lee had to make the hard decision of whether or not he should pursue McClellan any further. If he got too close, then the Union gunboats could cover McClellan's back, and he didn't want to let McClellan get reinforcements. Determined not let McClellan get back home with ease, he pursued him and the two forces once again met at Malvern Hill. This was one of the Union's best strategic positions for their had there artillery placed on top of Malvern Hill. Lee spent half the day searching for a good spot to attack the well positioned guns, but just decided to move his own in and try and drive them out with firepower. The attack wasn't really working, and to make matters worse, orders got mixed up. At or around 6 P.M. D.H. Hill's and Magruder's men tried to run their infantry up the hill. The result was a blood bath and no ground was gained. Although the battle was not won by the Confederates, the Union army still retreated back to the safety of Harrison's Landing and the Seven Days were over with.