One of the most formidable of these craft was the _Albemarle_, upon which work was begun early in 1863, at Edward's Ferry, several miles up the Roanoke River.

Iron was so scarce that the country was scoured for miles in every direction for bolts, bars and metal.

As stated by Maclay, the keel was laid in an open cornfield, and an ordinary blacksmith's outfit formed the plant for building; but the makers persevered and completed a craft 122 feet over all, with 45 feet beam and drawing 8 feet of water.
The casemate was 60 feet long, constructed of massive timbers, covered with 4-inch planking, over which were placed two layers of 2-inch iron.
The motive power was furnished by twin screws operated by engines of 200 horse-power each.

Her armament consisted of an Armstrong 100-pounder in the bow and another in the stern, the casemate being so pierced that the guns could be used at broadside or quarter.
At midnight, April 19, 1864, the _Albemarle_ gave a proof of her prodigious power of destruction.

On the preceding two days the Confederates had made a determined attack on Plymouth, held by the Union forces, and the ironclad now set out to render assistance.