As we look over Civil War books with good maps – we find the Formation of “Double Line” was very common during the last half of the war. The formation was formed by having half of the Brigade Regiments in line with the remaining Brigade Regiments deployed in the rear but with deployment distance – not stacked close up. In the Firebell rules, we should have a 1″ to 2″ open space between the Brigade lines (100 -200 yards). This space was important to give the rear regiments the space required to deploy as the Brigadier ordered, also if the front of the Brigade entered into a fire fight this space limited damage to the rear support regiments.
In 1861, the Brigade officers went to war with the tactics learned from the Mexican-American War, the Brigade forming all of its regiments in line for maximum fire power.
The tactics and terrain defined it’s use – (as a Brigadier leading 2,400 men the Brigade in line would be 1/2 mile long, could you see the end of your own formation or beyond and the threat to your flanks?)
Example, Antietam, the Union Iron Brigade, Gen. Gibbon in command, advances south to the battlefield during early dawn. The Brigade in March Column moves off the road, forming regimental columns of divisions (2 companies wide) with two regiments in front, with two trailing behind, two long lines made up a number of company lines. This Brigade formation of Double Line putting the unit into a battlefield formation, but not fully deployed into line yet.
AS THEY APPROACHED THE NORTH WOODS WHICH WAS IN THE FIRE ZONE OF MEADE’S BRIGADE, THE BRIGADE DOUBLE LINE DEPLOYED, TWO REGIMENTS IN THE FRONT – COLUMNS MOVING INTO LINE, THE TRAILING TWO REGIMENTS MOVING INTO LINE BEHIND THE FRONT TWO REGIMENTS. THEY MOVED AT COMMON TIME INTO THE WOODS, MOVING THROUGH THE PA RESERVES OF MEADE (passage of lines) INTO THE OPEN FIELDS SOUTH OF THE NORTH WOODS. NOW AT THE FRONT – TWO COMPANY’S WERE SENT FORWARD AS A SKIRMISH SCREEN, THE REGIMENTS WENT TO GROUND/HALTED, THE SECOND LINE ABOUT 100 YARDS BEHIND THE FRONT LINE. THE SKIRMISH LINE AT THE FENCE FOR THE CORN FIELD, ABOUT 200-300 YARDS IN FRONT. THE BRIGADIER HAS HELD HIS REGIMENTS IN DOUBLE LINE DUE TO THE TERRAIN (visibility) AND FOR IMPROVED MOVEMENT.
WHEN THE IRON BRIGADE ADVANCED ON THE ATTACK-SKIRMISHERS FELL BACK INTO LINE, THE BACK TWO REAR REGIMENTS WHEELED TO THE RIGHT TO BRING THEM ON TO THE RIGHT FLANK OF THE FRONT TWO REGIMENTS, NOW IN FULL BRIGADE FIRING LINE.
THE BRIGADE ENTERED THE CORN FIELD AND HISTORY.
Howard’s Brigade is sent forward, advancing south of the crossroads, moving to flank the Rebel line on Henry House Hill, working to stop the rebel advance and turn the battle. As Howard moved up the western slope, he left two regiments in line as support and advanced two regiments in line up Chinn Ridge to the crest – his Brigade formed “Double Line”.
This formation was not stacked with the ranks closed up, but with intervals between the front and rear lines to allow the support regiments to deploy (react) as needed. Well, we know this turned out bad, unless your underwear is grey. (Link for battlefield map)
Why would Howard do this? He was not certain of the situation, his flanks appeared to be in the air (no support). The combination of the crest line and woods limited Howard’s battlefield awareness. Howard’s attack was a cautious advance, giving him the flexible choice. Once he could see the enemy and know their position, the Brigade would form a four regiment firing line to launch the attack. In history, he would not have the time…
Hope these battle examples help in understanding the battlefield.