First encamped on East Capitol Hill upon their arrival in Washington, they soon moved to Arlington Heights, Virginia and afterward to Hunting Creek, where they went into winter quarters until March 1863.

On the request of President Abraham Lincoln, Secretary of War Edwin Stanton sent letters on 28 June 1863 to the commanding officers of the 25th Maine and 27th Maine regiments, asking for them to remain beyond their contracted service due to the invasion of Pennsylvania by Robert E. Lee and his army.

Declined first by the 25th Maine, the 27th was then asked, and over 300 men volunteered to remain beyond their service time in the defenses of Washington during what became the Gettysburg Campaign.

When Colonel Wentworth delivered the message to Secretary Stanton, he was informed that "Medals of Honor would be given to that portion of the regiment that volunteered to remain".

Following the end of the war, when the promise to award medals to the volunteers was fulfilled, there was a lack of an agreeable list of those who stayed behind in Washington.