William Stewart wrote:
i think it accomplished one very important thing. Confidence. in the Union Army. In the soldiers and the in the leadership.
Did it? From what I have read Hooker had done quite a lot to boost morale and espirit de corps with corps insignia and divisional colors. The cavalry engagement at Brandy Station has also been credited with giving the Union cavalry a boost in confidence as they finally managed a draw against Stuart's forces.
McClellan had turned Lee back in Maryland but I see no real boost in army confidence after that battle. The same, I think, could be said for Gettysburg in 1863. Both battles played out the same way where a major battle ended with a day of the two armies staring at one another over a bloody field to see if either side wanted to keep the battle going. In both instances Lee then retreated after giving his opponents an opportunity (perhaps a golden opportunity) to attack.
Meade quickly fumbled the offensive to pursue Lee and his next offensive fizzled out at Mine Run. It wouldn't be until May 1864 that the Federals in the east came at Lee again. Grant's celebrated refusal to turn back after the Battle of the Wilderness is well documented as a monumental shift in the Army of the Potomac's psyche of always falling back after a beating.
I'm just playing devil's advocate here so feel free to argue otherwise
