This Civil War battle resulted in 120 Medals of Honor

In 1863, Union soldiers attempted to root out deeply entrenched Confederate soldiers at Vicksburg, Mississippi. Repeated assaults failed to breach the defenses, leading to over 100 troops committing acts that would later earn them Medals of Honor for valor — including 78 soldiers who took part in a nearly suicidal attempt to build a bridge under fire.

Gen. Ulysses S. Grant at the Battle of Vicksburg.

(Library of Congress)

Vicksburg was the ultimate target of Gen. Ulysses S. Grant's campaign down the Mississippi. His assault started with a landing on the shore of the Mississippi on April 30, 1863, and he fought his way south in the battles of Port Gibson to Champion Hill and Big Black River.

Within weeks, Grant was outside Vicksburg, the city President Abraham Lincoln called, "the key to victory" and President Jefferson Davis called the "nailhead that holds the South's two halves together." The Confederates pulled back inside the "Fortress City."

The defenders were crouched in a ring of forts with 170 cannons, many aimed at bottlenecks and approaches to the city. Grant hoped to take the city before the defenders could truly settle in.

"First at Vicksburg" depicts the 1st Battalion, 13th Infantry Regiment which was the only unit to reach the top of the fortifications on May 19, but even they were later thrown back.

(U.S. Army)

He sent his infantry against an earthen fort named Stockade Redan on May 19, but they were repelled with 1,000 casualties. Grant spent the next two days coming up with a new plan.

He once again chose Stockade Redan, but the new plan called for two feats of combat engineering under fire. One feat was quickly erecting scaling ladders against the wall, a challenging but time-tested move. Before the ladders went up, though, a group of volunteers would need to cross a quarter-mile of open ground while under fire and construct a bridge across an 8-foot-wide ditch.

A call went out for 150 volunteers, only single-men need apply. They came and were split into three groups. The first group carried beams to span the gap, the second group carried the planks that would form the rest of the bridge, and the last group carried the scaling ladders.

These men were collectively known as "Forlorn Hope." Their assault was part of a three-phase operation. First was a four-hour artillery barrage, then the bridge construction and ladder emplacement, and then an assault by a brigade up the ladders.

On May 22, the barrage ended at 10 a.m., and Forlorn Hope sprinted out of the woods and across the quarter-mile as fast as they could.

The Siege of Vicksburg

(Thure de Thulstrup, U.S. Army)

But Confederate artillery and rifle fire quickly rang out, and an estimated half of Forlorn Hope was hit and down before they reached the ditch. The survivors quickly found that, with so few people still carrying the materials, they did not have enough pieces to construct the bridge.

They scattered, some attempting to take cover in the ditch or against the stockade wall as others ran back across the open field.

The assault went forward anyway. Three corps of Union soldiers attacked along the city's defenses and all three eventually took some section of Confederate fortifications. But all three were pushed back amid bloody, close-in fighting and the Union turned tail with 3,000 casualties.

The Siege of Vicksburg ends as Confederate leaders, near the center, walk out with a flag of truce to discuss surrender terms.

(Library of Congress)

Grant and his men were forced to conduct a siege that would drag on for six more weeks before the city finally surrendered. In 1894, 53 survivors of Forlorn Hope were awarded Medals of Honor for their heroism at Vicksburg, another 25 soldiers who took part in the failed effort would receive the same award in other ceremonies. Approximately 42 other Medals of Honor were awarded for actions during the siege and assaults, bringing the total to 120.

The Confederate forces had their own Medal of Honor, and Confederate Navy Capt. Issac Newton Brown received the medal for his actions on the CSS Arkansas while trying to fight past the U.S. Navy to relieve the pressure on Vicksburg.