Several Battles were fought. They are Known as the seven days battles.
men
Because it was the state capital of Pennsylvania, and a place of great military importance as a training centre for the Union armies, as well as a big rail junction.
general Robert E. Lee
In the battle of Fredericksburg, General Burnsides had General Hooker attack at one end of a 15 mile line and General Meade attack at the other end. General Hooker's attack failed miserably. General Meade's attack succeeded at first, but General Stonewall Jackson had prepared for such a situation and developed the technique of "Defence in Depth." General Meade was not ready for that and his front line had to withdraw. Since the Union Army was spread out over such a long stretch, General Burnside had been unable to send reinforcements to General Meade when it would have brought a Union victory.
John Bell Hood
Lee knew that if he managed to surround Washington, D.C., he could cut off Union states from their capital and bring Maryland into the confederacy.
After 1863, Union forces decided to focus their attacks on the Confederate, with the intent of destroying them and preventing the South from resisting Union advances. General Grant ordered five separate attacks. The Army of the Potomac would attack Robert E. Lee in Virginia. General Sherman would attack General Johnston in Northern Virginia, with his ultimate goal being the capture of Atlanta. These were the two primary Confederate armies. Grant also ordered a number of smaller attacks to weaken the Confederate armies by destroying its communications or its supplies. General Crook was to attack the Virginia-Tennessee Railroad. General Sigel was to attack the Shenandoah Valley. General Banks was to attack Mobile, and General Butler was to attack up the James River to threaten Richmond. All of the attacks except for Grant and Sherman's failed. Grant trapped Lee's army at Petersburg while Sherman captured Atlanta.
(A) General Lee wanted to take the pressure off General Grant's attack on Vicksburg, Miss. which would give the Union complete control of the Mississippi river, if Gen. Grant won the battle, (which he did). Gen. Lee hoped an attack in Penn. would take Union soldiers from Vicksburg, and that if Gen. Lee defeated Gen. Meade in Penn., then (B) Gen. Lee could attack Washington DC. (like the English did in the War of 1812), and Gen. Lee might even force President Lincoln to surrender the war against the South. (C) There were not a lot of Union soldiers in Penn. and an attack there by Gen. Lee would be totally unexpected, and give Gen. Lee the element of surprise.
The capital of the Union States was Washington D.C.
General Burnside
Moscow was the capital of the USSR.The capital city of the Soviet Union is Moscow.
A General of the Union.