The National Museum of Civil War Medicine in Frederick, MD, tries to debunk the widespread medical myth that anesthesia did not exist during the Civil War.
Gaseous ether and chloroform were both widely available and their therapeutic impact was well known in both Union and Confederate medical services. (Both had been used since the 1840s.) Major surgery was carried out using these anesthetics if they were available. It is estimated that greater than 90% of all major surgery was carried out with anesthetics. See http://www.civilwarmed.org/articles/myth_busters/
But neither ether nor chloroform was available before the 1840s, so Revolutionary War-era medical practices did not include the use of anesthetics.
Other medical misconceptions from the pre-anesthesia era abound. Ben Swenson, a historian and re-enactor who worked at Yorktown, VA, says visitors often approached him with incorrect assumptions. Something “we heard all the time that was patently false was that they would get soldiers rip roaring drunk before amputating an arm or a leg. There are actually a couple of misconceptions here. First, despite popular belief, they did not just take a hacksaw to peoples’ limbs. It was actually quite an intricate procedure involving skin and muscle knives, muscle retractors, saws, cauterizing irons, etc. And the alcohol thing is Hollywood history. Alcohol dilates the blood vessels and they knew that. They would not have wanted their patient to bleed to death. Besides, being drunk doesn’t dull the pain, it only changes your reaction to it. So no alcohol. And no again, they didn’t give someone a bullet to bite on…when someone cuts into you, you scream, and that bullet goes down the gullet. A stick would probably have been used to keep someone from biting his tongue off.”
So the absence of anesthesia is a myth if it’s said to pertain to the Civil War, but true during the Revolutionary War.