“… a surprise in order to insure success.”: Gillmore’s Plan for Morris Island

Since taking command of the Department of the South, Brigadier-General Quincy Gillmore worked with a single focus in mind – Morris Island. That barrier island was the first advance, he thought, toward Charleston. And Charleston was his objective. Having taken stock of the situation, and consulted his subordinates, Gillmore decided to use the foothold which Brigadier-General Israel Vogdes built on Folly Island as a spring-board onto Morris Island. There Gillmore would practice the art of siege, in which he’d earned a great reputation the year before, and destroy Fort Sumter.

Gillmore’s naval counterpart, Rear-Admiral John Dahlgren, arrived to assume command of the South Atlantic Blockading Squadron on July 4, 1863. In conference with Gillmore, Dahlgren agreed to support the plan. If successful, the Army would open the door to Charleston for the Navy to follow through.

On the surface, the plan was complex but played directly against Confederate weaknesses and sensitivities:

The project for obtaining a lodgment on Morris Island comprised three distinct operations.

First. The real attack from Folly Island to partake of the nature of a surprise.

Second. A demonstration in force on James Island, by way of the Stono River, designed to prevent re-enforcements to the enemy on Morris Island from that quarter, and, if possible, draw a portion of the Morris Island garrison in that direction.

Third. The cutting of the Charleston and Savannah Railroad at Jacks[on]borough by ascending the South Edisto River, in order to delay re-enforcements from Savannah, should the real attack be temporarily checked or prematurely divulged.

I’ve depicted these three operations in light blue on the map below (with dashed blue indicating the Federal lines and solid green line depicting the railroad):


In addition to interdicting reinforcements, the move against Jacksonborough touched General P.G.T. Beauregard’s very sensitive nerve on the Charleston & Savannah Railroad. Colonel Thomas Higginson and the 1st South Carolina Volunteers (later the 33rd USCT) received that mission.

Likewise, the feint against James Island touched another sensitive spot – a potential “back door” to Charleston. Brigadier-General Alfred Terry commanded a division (which dressed out more as a reinforced brigade with about 3,800 men) for this assignment. Troops in this expedition included the 2nd South Carolina Volunteers and the 54th Massachusetts Infantry. The force moved with support of two navy gunboats and a mortar schooner. If successful, this feint would pin down significant Confederate forces that otherwise might shift to Morris Island.

But the main effort fell on Morris Island. Gillmore took stock of the difficulties of such an assault across open water. So to improve the odds, he took great pains to conceal the buildup of forces. “It was necessary that the attack on Morris Island should be a surprise to insure success. Secrecy was, therefore, an essential element in the preparations.” This not only included concealment of troops and artillery, but also timing of the arrival of transport ships from Hilton Head. As set forth on July 8, the plan looked as such (my most colorful map yet!):


Command of the assault fell to Brigadier-General George Strong. As a precursor to the main assault, a small force to exit Folly Island Creek, then across Light House Inlet, to “enter the creek to the west of Morris Island, and will land just north of the old light house, seize the batteries there, and, if possible, turn them upon the enemy’s encampment north of them.” This force was to start movement on the evening of July 8.

The main force, roughly four regiments in size, would “land from Light-House Inlet, carry the batteries on the south end of Morris Island, and advance to the support of the detachment above mentioned.” This force would launch its crossing before daybreak on July 9.

Supporting this crossing, the thirty-two rifled pieces and fifteen mortars in Federal batteries on Folly Island would open fire at daybreak on July 9. A force of four boats armed with boat howitzers would work down the inlet to suppress the Confederate defenders. Moving up the ocean side of Morris Island, four monitors would fire shot, shell, and, if in range, grapeshot. Gillmore held two additional regiments and a force of artillery in reserve on Folly Island.

To support exit of Folly Island Creek, Gillmore ordered Colonel Edward Serrell, 1st New York Engineers, to remove pilings erected earlier by Federals to obstruct that waterway (depicted in yellow on the map above). Serrell employed a floating saw similar to that used along the Mississippi a year earlier to clear river snags and trees.


Serrell’s engineers began this work on the evening of July 8, eventually clearing a path 32 feet wide. Serrell reported “a pile 10 or 12 inches in diameter was cut off in an average length of time of from six to seven minutes.” After clearing the pilings, Serrell turned his attention to preparing a bridge to span the inlet. He’d constructed what we’d call today a pre-fabricated bridge at Hilton Head.


The plan was to lay that bridge on the morning of July 9.

Gillmore posted orders for all these moves to start on the evening of July 8, 1863. But bad weather caused a postponement until the evening of July 9. The delay necessitated modifications to the plan. Terry’s feint had already sailed up the Stono River by this time and was not recalled. But the main assault force received orders dictating a new arrangement for crossing:

I. The attack on Morris Island, ordered for this morning but postponed in consequence of the inclemency of the weather and other unfavorable circumstances, will take place to-morrow morning at break of day by opening our batteries at the north end of Folly Island. General Strong’s brigade, or so much of it as the small beats can accommodate, will embark to-night, and hold itself in Folly Island Creek, ready to move forward, and at the proper time occupy the south end of Morris Island.

II. Lieut. Commander Francis W. Bunce, U.S. Navy, with four navy howitzer launches, will approach Light-House Inlet at daybreak, by way of Folly Island Creek, and engage the enemy’s rifle-pits and batteries on Morns Island in flank and reverse, choosing his own position. He will cover General Strong’s landing.

III. Two regiments of infantry, a battery of light artillery, and five Requa rifle batteries will be held in readiness to re-enforce General Strong promptly. Brigadier-General Seymour will arrange and order all details….

Thus simplified, the plan looked like this:


Thus ordered, the attack would take place on July 10. Let’s call it what it is – a shore-to-shore amphibious operation. Tally up the “interesting” facets to the operation: counter-battery bombardment, engineer obstacle clearing, amphibious landings, escorting gunboats (with howitzers), and ship-to-shore bombardment. Add in the use of the Civil War equivalents of a Bailey Bridge and machine gun. Littoral operations are never simple affairs!

(Citations from OR, Series I, Volume 28, Part I, Serial 46, pages 6-11 and 226.)

Published by Craig Swain

"Historical marker hunter" and Civil War enthusiast.

4 thoughts on ““… a surprise in order to insure success.”: Gillmore’s Plan for Morris Island

  1. Just discovered your site today (July 8, 2013). Very nice and informative.
    Would like to ask where you found the map you use for the Charleston & Savannah RR discussion. I am doing research on Suffolk, Va and the Federal Fort Dix and that type of map seems just the type if one could be obtained.

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