"The Men Dig,Dig,Dig"
— Civil War Trail —
Late on March 26, C.S. General St. John Liddell withdrew into the relative safety of Fort Blakeley and Spanish Fort, Liddell, assisted by General Francis Cockrell, assumed personal responsibility for the defense of Blakeley and put the defense of Spanish Fort in General Randall Gibson's capable hands. On the morning of the 27th, A.J. Smith, leaving an entrenched division at Sibley's Mills, wheeled around and closed in on Spanish Fort's left flank, near Bay Minette. Granger and Bertram simultaneously closed in on the fort's center and right flank respectively.
Gibson, not one to sit on his hands, responded aggressively. At dawn 550 Confederates slipped out of Spanish Fort, marched deliberately toward Granger's line, and fired a sudden, unexpected volley into the ranks of the 47th Indian and 161st New York, forcing them back in confusion. Yelling like demons, the Rebels then charged boldly into a gap they had created. Later that morning Colonel James William's 21st Alabama, hidden in bushes near the burned Bay Minette Bridge, surprised Smith's forces with a volley from 225 defiant muskets. Soon forced back to their lines, these skirmishers did nothing more than momentarily delay the inevitable investment of Spanish Fort, but they did let the Yankees know they were in for a fight.
From the edge of the woods east of the Confederate stronghold lay a sloping plain- filled with fallen trees and naked stumps for a thousand yards, tangled abates fifteen feet wide, a ditch eight feet wide by five feet deep, a line of rifle pits, breastworks of timber and earth ten to fifteen feet high, six redoubts bristling with cannon muzzles, a hundred foot bluff, a bastioned water battery, and the Blakeley River. Torpedoes, which sank three ships during the siege, guarded the fort's water approaches. Hundreds of subterra shells (land mines) similarly protected its landward approaches. Gibson's batteries mounted 47 field guns, Coehorn mortars, and heavier guns, including Columbiads, Parrots, and Brooke Rifles. The enterprising garrison of 1,810 men- which included at least one company of black artillerymen- while digging day and night to strengthen the works, placed steel plates over the embrasures to protect the artillerymen and made wooden mortars from gum stumps to add to the fort's fire power. The fort was weakest on its extreme left. It had not been fortified there, because it bordered a nearly impassible swamp.
Canby's division fought through the tangle of trees to tighten the cordon around the fort from north, south, and east, Gibson's line, bright with "fluttering battle flags," opened its guns on the enemy. His skirmishers, using trees and hills for cover, engaged the Yankees in an active defense along their entire front but were pushed steadily back. A little after noon, Canby's field guns finally began to answer the Rebel batteries. In front of the Confederate's strongest bastion on the forward line, Fort McDermott, Granger's and Bertram's regiments met stiff resistance from artillery fire and musketry. Through the fallen trees made progress difficult, the Federals pushed the southerners back to the fort and set up the 7th Massachusetts Light Battery within 750 yards of McDermott's 25foot ramparts. By nightfall, Canby's front lay with a thousand yards of Gibson' s main works along the line. General John McArthur, asked if he thought the Federals should assault Spanish Fort, replied, "My division will go in there if ordered, but if the Rebels stay by their guns, it will cost the lives of half my men." Saying, "It won't pay," Canby set the men to work entrenching.
Using the spade, the pick, and the ax, Canby would take Spanish Fort by digging zigzag approaches toward and trenches parallel to Gibson's breastworks. His skirmishers, sometimes firing almost muzzle to muzzle, sought to keep the Rebels' heads down, while the men dug night and day. Gibson sent out at least 12 sorties in an effort to delay the inevitable. In the most successful, on March 31, Captain Clement Watson, Gibson's inspector-general, let 16 officers and men out of Fort McDermott under cover of smoke at sunset Watson captured Captain R.B. Stearns of the 7th Vermont Infantry and twenty of his men and escorted them back to McDermott. This exploit made the Yankees more cautious, and Gibson's vigorous defense led some to believe the Rebels had up to 15,000 men within the fort.
"Our rifle pits are some of them [as of April 6] within 150 yards or so of the Rebel forts a& batteries — the men dig, dig, dig, day & night, with accoutrements on, & their trusty rifles by their sides in the trenches. The Rebels dig too, and we have to be cautious not to expose ourselves too far, or whiz goes a bullet, much too close to one's head to be pleasant for a timid man. Sometime they rain around us like hail, and I wonder that the casualties are so few." Captain Thomas N Stevens, 28th Wisconsin Infantry.
Both sides made mortars of three-foot sections of logs, of eight gum or oak, bored out at one end. These could be strengthened with iron hoops, lined with sheet iron, and used in the trenches by two men. A small charge of power would throw a shell with a short fuse into the enemy's works.