Vicskburg Campaign-The Navy Unloads Its Firepower.

One of the chief reasons for Union victory in the West was the close
cooperation  between General Grant and Admiral Porter.

While the the Navy bombarded Port Hudson from the river and land, Admiral Dixon Porter set up a similar operation for Vicksburg itself. The admiral had the USS Cincinnati, Mound City, Carendolet, Benton, and Tuscumbia approach within 300-400 yards of the Confederate guns.  The two sides exchanged shots for over two hours before the Union squadron withdrew.  Porter often coordinated closely with General Ulysses S. Grant's ground assaults.  It was during one of these raids that Confederate gunners found their mark on Cincinnati, striking the ironclad in several critical places.  The ironclad soon sank.

Porter's ships bombarding Vicksburg at night.

Direct assaults did not make much progress.   Union leadership decided on a  more passive siege.  Ground forces would bombard from land, while Porter deployed a number of heavy guns from river and land to shell the fortress town.  Porter brought up mortar boats equipped with 175 mortars (not all of them functioning) from the south to augment his ironclad squadron. 

In addition to his warships, Porter placed IX-Inch and X-inch Dahlgrens and 100 pounder Parrott Rifles on scows (flat bottom river boats).  On land, he contributed five VIII-inch and two IX-inch Dahlgrens, two 42-pounder rifles, and older 32-pounder smoothbores.  All the guns were added to Grant's artillery batteries and manned by sailors from Porter's squadron. From 27 May to 3 July 1863,  Porter's gunners bombarded Vicksburg.  The gunners usually fired either first thing in the morning or at night, as Porter did not want to exhaust his gunners during the hot summer days. 

"Siege of Vicksburg"-Compare this print to the war time sketch
 of the same scene by Theodore Davis.

Porter directed the gunners not only to fire at the town, but also at the town supply depots, such as its cattle herd. The bombardments killed several hundred heads of cattle, making the Confederate's supply situation that much worse. 

One target Porter directed his gunners to stop firing at was the infamous "Whistling Dick" gun.  "Dick" was an 18-pounder rifle that made a distinct "whistling" sound when fired.  It is credited with sinking Cincinnati.  After many failed attempts to knock the gun out, Porter told his ships not to specifically target it anymore. 

In addition to the massive bombardment, Naval forces assisted in keeping Confederate relief columns from coming to Vicksburg's rescue. Porter deployed Brigadier General Alfred Ellet's Mississippi Marine Brigade to help Union ground forces fend off approaching enemy units.  This unique formation now under Navy control was a combined unit of infantry and cavalry with its own river transports.  The unit also took control of plantations along the river where newly freed slaves produced cotton for Union forces.

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Porter received a note during the siege indicating that Admiral Andrew Hull Foote died in a New York hospital on 27 June.  Considered one of the Navy's finest seamen (and rabid teetotaler), he suffered an injury during the Fort Donelson campaign which he never fully recovered from.  He was to take over the South Atlantic Blockading Squadron, but his injury prevented him from travelling.  All the ships in the squadron lowered their flags to half mast. 

The Unfavorable Mortar Boats

In the later fall of 1861, Captain (later flag officer) Andrew Foote inherited a squadron in the making. The warships under construction and conversion at yards along the Mississippi and Ohio Rivers were far from the ocean going vessels Foote was accustomed to. In a private letter to Army Quartermaster-General Montgomery Meigs, dated November 20, 1861, Foote confessed is dislike for some of the vessels, but saved special criticism for the mortar boats being fitted out:

I have not, fortunately, committed myself in relation to them, although I have a written order from General Fremont to man, arm, and equip them. I never have thought favorably of these boats, either in construction or as an element of power. Still as they were built, and the mortars (12) built, I concluded to move in the matter and kept you informed, or rather asked your authority to go forward. (ONR, Series I, Volume 22, page 438.)

These river mortar boats, not to be confused with larger schooner mortar boats used by the blue-water navy, that Foote wrote of were little more than rafts. A pair of these boats appear in a wartime photo, tied up alongside the USS Tuscumbia.



The mortar boats were, as Foote indicated, a project begun by General John C. Fremont in the early days of the war. The mortars themselves came from Fort Pitt Foundry in Pittsburgh. These 13-inch Seacoast Mortars, Model 1861 - the Army's latest and heaviest seacoast mortars. The Army Ordnance Department designed the weapon to arm coastal fortifications. The 13-inch mortar fired a 227 pound shells fired to a maximum range of 4600 yards. Unlike standard guns, the mortars fired the shells in a high, arching trajectory to fall on top of the intended target. The army designed these seacoast mortars to drop shells upon an enemy bombardment fleet attacking coastal fortifications.



But with wartime needs along the Mississippi River, Army leaders saw an offensive potential with the mortars. Mortars, they felt, could provide a "stand off" bombardment of river fortifications. This concept gained favor in public opinion outside the military, suggesting less bloody means of opening the river.

Trouble was the eight and a half ton mortars were not very mobile. Normally the Army would move such heavy weapons as part of a siege train. But the swampy bottom lands of the river precluded employment such ponderous formations. Instead Fremont opted to float the mortars into position.

Using a typical flat bottomed barge as a basis, the constructors added a platform of timbers. The platform measured roughly 60 feet by 25 feet. Bulwarks, six to seven feet tall, formed a superstructure on top of the platform. Inside the space formed by the bulwarks was room for the mortar, its bed, and handling equipment. Contemporary drawings show the mortars placed on the center line, but in the photo the mortar sits just to starboard.

With all the mortar and equipment inside the bulwarks, there was no room for crew accommodations or any propulsion system. Tugs moved the mortar boats into position, and provided transportation for the fifteen man crew. Additional boats served as floating magazines and berthing facilities. When firing, the crews stood on the aft end of the mortar boat, or when possible, walked out onto shore, to avoid the overpressure blast when the big weapon fired.


Foote inherited the mortar boats as part of the Mississippi River Squadron. Lacking any practical experience with mortars he turned to the Army for help. Initially Captain Archibald G.A. Constable of the 11th Ohio Independent Artillery served as an adviser. Later the Army sent Captain Henry E. Maynadier, a regular army artillery officer.

Charged with supervising the completion of the mortar boats, Foote faced several delays. The progress of the mortar boats received a high level of visibility. On January 23, 1862 President Abraham Lincoln requested a daily report on the progress. The mortars themselves, being a new pattern, were slow arriving in quantity. Mortar beds were also in limited supply. As the material arrived, Foote complained he lacked another key resource - personnel. The Army eventually provided many of the gunners required. By March Foote had over thirty mortar boats ready for use.

Foote employed the mortar boats at Island No. 10. Later the mortar boats carried the fight to Fort Pillow further downstream. Progress on the river mortar boats paralleled similar outfitting for the blue-water mortar boats. Admiral David Farragut prepared ocean-going mortar schooners to bombard Confederate defenses downriver from New Orleans.

In practice the mortars failed to live up to their promise. Long range indirect fires required coordination to adjust the fall of the projectile onto the target. Although balloons were used at Island No. 10, the mortar shell trajectory was simply too unpredictable for proper fire control. Although impressive to both sides, the mortars offered little practical impact on the Confederate fortifications. Long range, indirect fire support from warships had to wait a few decades for more advanced technology - better guns, projectiles, propellants, and communications.

But those mortar boats provide a fair example of the nature of Army-Navy cooperation, even if at times acrimonious, in the early stages of the war. Both services would put the 13-inch mortars to good use later in the war.

Illustration Credits: Naval Historical Center, Battles and Leaders, Author's personal collection.