It's Stonewall Jackson's birthday - here's the story of his left arm's separate grave (bonus: Lord Uxbridge's leg)

From the always interesting Atlas Obscura:

Most of Civil War superstar Thomas Jonathan "Stonewall*" Jackson (wiki) was buried in a Lexington, Virginia, cemetery that now bears his name, but he was so famous at the time of his death that his amputated left arm was spirited away to its own separate grave.

It was just after dark on May 2, 1863. Jackson had just launched a devastating attack against Union forces at Chancellorsville. Returning to his own lines with several staff officers, Jackson, ever the aggressive soldier, decided to conduct reconnaissance in the area. As he and his staff rode through the woods near Confederate lines, a North Carolina regiment, unable to see who was riding up on them, opened fire. Jackson was struck by three bullets, two of them shattering his left arm.** The general was evacuated from the area and given medical treatment, but the arm couldn't be saved and was amputated. Pneumonia set in, and on May 10, 1863, the South lost its most effective tactician. While Jackson's body would travel to Lexington, where he had taught before the war, his severed arm would receive its own burial.

Two-armed Thomas 'Stonewall' Jackson
during the Mexican-American War, 1847

Thinking that the limb of so great a solider was too precious to simply throw on the regular body part trash pile, Jackson's unofficial company chaplain, Reverend Tucker Lacy wrapped the arm in a blanket and took it his family cemetery. The reverend gave the limb a standard Christian burial and placed a marker above the site.

Supposedly Stonewall Jackson's arm was dug up and reburied numerous times in the ensuing years and there is no concrete evidence that it still resides in its original burial space, but the simple gravestone remains to remember one of the oddest instances of hero worship in the history of battle.

* Jackson rose to prominence and earned his most famous nickname at the First Battle of Bull Run (aka First Manassas) on July 21, 1861. As the Confederate lines began to crumble under heavy Union assault, Jackson's brigade provided crucial reinforcements on Henry House Hill, demonstrating the discipline he instilled in his men. Brig. Gen. Barnard Elliott Bee, Jr., exhorted his own troops to re-form by shouting, "There is Jackson standing like a stone wall. Let us determine to die here, and we will conquer!"

The Death of “Stonewall” Jackson
Currier & Ives (1872)

When Jackson died on May 10, 1863, his attending physicians attributed the death to a pneumonia Jackson had developed four days after amputation of his arm. The infection was believed to be secondary to a pulmonary contusion, or bruised lung, that Jackson may have suffered after falling from a stretcher during his removal from the field. For nearly 150 years, that diagnosis was largely unchallenged. 

More recently, however, modern physicians have begun offering alternate possibilities for his cause of death.The most commonly suggested alternative is pyemia, or blood poisoning. Known today as sepsis, pyemia was a well-recognized and deadly condition during the pre-antibiotic days of the Civil War.

** The story of Stonewall Jackson's injury always reminds me of this, from later in the War of Northern Aggression (wiki):

"They couldn't hit an elephant at this distance."

~ Union general John Sedgwick (died 1864) (just before being killed by Confederate fire at the battle of Spotsylvania)

Uxbridge's false leg

Related, via Andrew Stuttaford - read the whole Wikipedia entry: Lord Uxbridge's leg was shattered by a cannon shot at the Battle of Waterloo and removed by a surgeon. The amputated limb went on to lead a somewhat macabre after-life as a tourist attraction in the village of Waterloo in Belgium, where it had been removed and interred.

Per Wikipedia:

Just after the Surgeon had taken off the Marquis of Anglesey's leg, Sir Hussey Vivian came into the cottage where the operation was performed. "Ah, Vivian!" said the wounded noble, "I want you to do me a favour. Some of my friends here seem to think I might have kept that leg on. Just go and cast your eye upon it, and tell me what you think." "I went, accordingly", said Sir Hussey, "and, taking up the lacerated limb, carefully examined it, and so far as I could tell, it was completely spoiled for work. A rusty grape-shot had gone through and shattered the bones all to pieces. I therefore returned to the Marquis and told him he could set his mind quite at rest, as his leg, in my opinion, was better off than on."

I love this bit: 

According to anecdote, he was close to the Duke of Wellington (at Waterloo) when his leg was hit, and exclaimed, "By God, sir, I've lost my leg!", to which Wellington replied "By God, sir, so you have!"

Further reading: Rebel Yell: The Violence, Passion, and Redemption of Stonewall Jackson