When Charles H. T. Collis raised a small company of men from Philadelphia called the Zouaves D’ Afrique on August 17th, 1861, Edward T. Marion was one of those men who enlisted himself to serve with Captain Collis. This small unit donned the French-inspired Zouave uniforms, and due to their remarkable service in the Shenandoah Valley in 1862, Captain Collis was directed to raise an additional nine companies from Philadelphia for an entire Zouave regiment. Ultimately, the 114th Pennsylvania Infantry was formed with Collis as colonel, and Edward with the rest of the Zouaves D’ Afrique were transferred in. The 114th Pennsylvania would wear their unique Zouave uniforms for the rest of their service. Edward was promoted to 1st Sergeant of Company I, 114th Pennsylvania Infantry upon consolidation, serving in this capacity through the Fredericksburg, Chancellorsville, Gettysburg, Bristoe, and Mine Run campaigns. Prior to the Overland Campaign, Edward was promoted to 1st Lieutenant on March 26th, 1864. The 114th Pennsylvania would be assigned to the Provost Guard of General Headquarters for Major General George Meade and the Army of the Potomac on April 18th, 1864. Even though the picketing and post duties kept Edward and the 114th Pennsylvania away from the front lines for the most part during the Overland and Petersburg campaigns, it would be at the beginning of the Appomattox Campaign and the fall of Petersburg that Edward and the Philadelphians found themselves in a great struggle.

On April 2nd, 1865, General Ulysses S. Grant ordered assaults along the entrenched Confederate lines around Petersburg, hoping to break through and put General Lee’s rebel army into full retreat. The 114th Pennsylvania was sent to the front, and in the front lines of the assault, Edward and his comrades in Zouave dress charged handsomely upon the Confederate works, capturing a portion of the earthworks opposite Fort Hell after others had failed to do so before them. Despite the success, it came with a heavy cost to the regiment. Among the casualties was 1st Lieutenant Edward Marion. He would be killed in action during the charge and capturing of the rebel works in the U.S. breakthrough at Petersburg.