Three hundred and eighty five men of Col. Joshua Lawrence Chamberlain’s 20th Maine Regiment held the Union Army’s left flank on July 2, 1863. Posted on a hill called Little Round Top they were repeatedly attacked by Confederates of the 15th and 47th Alabama. Ammunition was running short. The next Rebel assault might overrun the position. Chamberlain’s order rang out, “Bayonets!” In a downhill charge depicted in the 1993 film Gettysburg, the Yankees routed the Rebels, capturing 400 prisoners. Probably the most famous bayonet charge of the war, it was one of the few that succeeded.
The origin of the bayonet lies 200 years earlier in France. Bayonne, in the Basque country, produced a hunting knife called a bayonette. According to legend, in 1647, German cavalry charged a regiment from Bayonne. The musketeers jammed their tapered knife handles into the muzzles of their weapons, making improvised pikes to fend off the attacking horsemen. Jean Martinet (died 1672) whose name became an epithet for harsh drillmasters, is credited with issuing bayonets throughout the French Army. By the 1660s most European armies carried “plug bayonets.”
At Killiecrankie in 1689, a wild charge of Scottish highlanders fighting for James II routed a larger force of Royalists fighting for King William III because the Royalists delayed fixing their bayonets. The plug bayonet was a short-lived innovation; it had to be pounded out of the barrel to fire the weapon, and it is surprising so many survive in pristine condition in museums and arms collections.
The bullet is a fool; the bayonet is a clever fellow.
– Marshal Aleksandr Suvorov (1729-1800)
Invention of the socket bayonet in 1678 is credited to Marquis de Puységur (1656-1743) Marshal of France under King Louis XV. The blade had a collar that fitted over the muzzle, and was offset, to allow loading and firing. Early socket bayonets had an unfortunate tendency to fall off the weapon at inconvenient times. By the early 18th century, spring-loaded locking lugs allowed bayonets to be securely fixed and quickly unfixed.
In the 19th century, the bayonet design diverged down two paths: spikes and swords. Spike bayonets were pure thrusting weapons; sword bayonets could thrust or slash. The British “Brown Bess” musket (in service 1722-1838) had a 17-inch (43 centimeter) spike. The “Baker” rifle of the same era, with a shorter barrel, carried a 24-inch (61 centimeter) sword bayonet, allowing a mixed square of riflemen and musketeers to present a more uniform line of points.
Rifled muskets of the American Civil War mostly carried spike bayonets. Raised on a steady diet of Napoleonic doctrine, officers on both sides believed the bayonet was “the weapon of the brave,” and massed charges by dense columns were the key to victory. In 1852, as a captain of engineers, George B. McClellan (1826 -1885) translated and published a French Army bayonet drill manual. It taught a system of bayonet “fencing” utterly impractical for battlefields that had been transformed into killing grounds by the increased lethality of the rifled musket. In his preface, McClellan wrote:
“There is an instance on record of a French grenadier, who, in the battle of Polotsk,  defended himself, with his bayonet, against the simultaneous attack of eleven Russian grenadiers, eight of whom he killed. In the battle of Sanguessa,  two soldiers of Abbé’s division defended themselves, with their bayonets, against twenty-five Spanish cavalry, and, after having inflicted several severe wounds, rejoined their regiment without a scratch.”
In reality, the bayonet was a psychological weapon. Fighting rarely came down to “cold steel” versus warm flesh. Either charging attackers would be shot to pieces before they could close, or defenders would break and flee.
The evidence was in the medical reports. Few bayonet wounds were inflicted in the Civil War. Of those reported, many were men already felled by gunfire, bayonetted in the field. Between May and July 1864, a period that saw the brutal battles of the Wilderness,
Spotsylvania, Cold Harbor, and the Crater, surgeons of the Army of the Potomac treated exactly 37 bayonet wounds. In his memoirs, Gen. William T. Sherman (1820-1891) recalled that in close fighting, men fought with clubbed muskets, not bayonets.
European armies uniformly ignored the lessons of the Civil War and retained their mystical faith in the cult of the bayonet. Against machine guns and barbed wire, the result was a predictable bloodbath when the world went to war in 1914.
“Well, governor, we also have fewer horses and bayonets, because the nature of our military’s changed.”
– President Barack Obama to Gov. Mitt Romney, Presidential Debate, Oct. 22, 2012
The last American bayonet charge was in Korea in 1951. The Army has largely abandoned bayonet training. Marines however, consider this an important infantry skill, noting that bayonets never run out of ammunition.
In September 1943, the Army’s bayonet manual, defined the “Spirit of the Bayonet” for the Greatest Generation:
“The will to meet and destroy the enemy in hand-to-hand combat is the spirit of the bayonet. It springs from the fighter’s confidence, courage, and grim determination, and is the result of vigorous training.”