The moment that the Norfolk Navy-Yard
was evacuated, the erection and armament of batteries along the Elizabeth River
was begun to prevent its recapture; and thus Virginia
came into possession of a thoroughly equipped navy-yard, at which the Merrimac
, some time later, was converted into the ironclad Virginia
, and the guns needed for the speedy armament of batteries for the defense not only of the Elizabeth
, and York rivers
, but also against attacks on Norfolk
by other lines of approach, were obtained.
Subsequently, the Virginia Corps
of Engineers was merged into that of the Confederate States
; and the cost of completing the defenses begun by the State of Virginia
was borne by the Confederate Government.
Very few of the officers in the Confederate
corps had any previous practice as military engineers, although some of them had been educated at military academies.
In this respect the North
had a decided advantage over its opponents.
No engineer troops were provided for by the Confederate Congress until 1863, when two regiments were authorized and organized, in time to take part in the campaigns of 1864.
Prior to that time, such duties as pertain to engineer troops were performed by details from divisions, generally known as Pioneer Corps, under the direction of officers of the Engineer Corps attached to such divisions.
Of the two regiments of engineer troops, the First Regiment and two companies of the Second Regiment were organized for service with the Army of Northern Virginia.
The other eight companies of the Second served elsewhere than in Virginia
, several of them in the Trans-Mississippi Department.
During the first three years of the war when pontoon bridges were needed, they were handled by the Pioneer Corps
, or other details from the ranks, under the direction of officers of the Engineer Corps.
The bridge on which General Lee
's army recrossed the Potomac
after the battle of