In April 1864, the 97th was ordered north to Virginia so as to join General Grant's push toward Richmond. They became part of General Butler's Army of Virginia and North Carolina. During the next twelve months, the 97th saw it's most intense and frequent combat. In May alone, the regiment fought at Bermuda Hundred, City Point, Swift Creek, Proctor's Creek, operations against Fort Darling, the battle of Drewry's Bluff, and the devastating battle of Green Plains. During the battle of Green Plains, the regiment was attacked by a full division under the command of General Pickett. The 97th was unsupported and suffered 47 killed, 123 wounded and 12 captured. The 97th then participated in the battle of Cold Harbor and the siege operations against Petersburg. While in the trenches outside Petersburg, the regiment was on the right flank of the ill executed Battle of the Mine. On September 1, 1864, the regiment received a new flag to replace its three year old battle-worn banner.
During this period, the 97th "behaved gallantly and were steadfast in their duty". The regiment, several of its officers, non-commissioned officers, and a private were praised in a letter by General Butler dated October 11, 1864. By October 29, according to Guss's history of the 97th, the regiment numbered only 483 due to injuries, deaths, capture, desertions, and finished enlistments. All of the original officers except Col. Pennypacker had by this time been discharged or mustered out of service. In November, the regiment was reinforced with about 150 men who came from many parts of Pennsylvania. The regiment set up winter quarters Chapman's Farm, Virginia.