Charles Francis Adams Jr., a Union captain during the Civil War, hated how Civil War horses suffered. In a letter to his mother, Adams wrote, “You have no idea of their sufferings... I do the best I can for my horses and am sorry for them; but all war is cruel... a horse must go until he can’t be spurred any further and then the rider must get another horse as soon as he can seize one.”
Over a million horses perished in the Civil War. By the end of the conflict, fallen horses outnumbered fallen men 2-to-1. The roles of horses in the Civil War included riding into the field, where they faced gunfire and cannon balls, carrying cavalrymen hundreds of miles, and transporting artillery and goods. Civil War horse breeds like the Morgan, American Standardbred, and American Thoroughbred fought on both sides of the bloody conflict.
Without their horse advantage, the North might not have won the clash. But what was the conflict like from a horse's perspective?
The Number Of Fallen Horses Was Double That Of Humans
Even in the 21st century, the Civil War remains the bloodiest conflict in American history. An estimated 620,000 men fell, dwarfing US losses in WWI and WWII. But the horse toll during the Civil War was double that number. According to historian Gervase Phillips, around 1.2 million horses and mules perished during the conflict.
While many horses perished on the front lines, thousands more starved or passed from neglect. Union Quartermaster General M.C. Meigs complained that soldiers weren't caring for their horses well enough. In response to a demand for more horses from a major general, Meigs wrote, "We have over  regiments of cavalry, and they have [slain] ten times as many horses for us as for the Rebels."
In the early days of the clash, many troops neglected their horses. According to the Comte de Paris, during the first year of the conflict, "More than one [Union] regiment used up three horses to every man... it was only through the severest discipline that troopers were taught at last to take care of their horses."
Armies left fallen horses in their wake, according to Captain Charles Adams. He described the devastation suffered by horses in 1863, "The air of Virginia is literally burdened today with the stench of [fallen] horses, federal and confederate. You pass them on every road and find them in every field, while from their carrions you can follow the march of every army that moves.”
Soldiers Desperate To Escape The Front Lines Sometimes Mistreated Or Sold Their Horses
Making sure soldiers had mounts and remounts was a major challenge during the conflict. The Confederacy tried to get around the challenge by ordering cavalrymen to provide their own horses. In the North, the military quickly shipped in horses from Vermont and Kentucky during the first months of clash.
The Comte de Paris reported "immense corrals... among the vacant lots in the neighborhood of Washington and the Western cities." These lots were soon crowded with horses who were "carelessly picketed, badly fed, seldom groomed, and without any shelter."
Replacing lost horses was such a problem that soldiers sometimes took advantage of the shortage for their own gain.
Confederate Major E.H. Ewing complained, "When a soldier is dismounted he is entitled to a furlough of  days to go home and remount himself. This makes [cavalrymen] mere horse traders, selling their animals whenever they desire to go home."
In 1864, Private J.N. Cummings of the South Carolina calvary proved Ewing right. He wrote to his wife complaining of a fever, and though it was improving, Cummings explained, "I have sold my horse to a dismounted man and will come home soon."
Union officers also complained that men were neglecting their horses on purpose so they could escape the front lines.
During Skirmishes, Both Sides Targeted Their Enemy's Horses
In a March 1862 skirmish, Union officers Colonel Phelps and Colonel Dodge each had three horses shot from under them. One horse was even "struck by 20 balls" before falling. After an 1861 skirmish, another major reported, "Many of my officers, non-commissioned officers, and even privates, had three or even four horses [slain] under them."
The numbers were even higher on the Confederate side. One general, J.O. Shelby, had 24 horses shot from under him during the conflict. Nathan Bedford Forrest lived as 39 horses were shot from under him.
Horse fatalities were high during confrontations because both sides targeted their enemy's mounts. Healthy horses carted artillery to the front and helped enemy soldiers escape. Officers may have seen slaying enemy horses as a way to limit human casualties. After all, if horses weren't available to haul a cannon to the skirmish, it would save human lives. Captain Adams felt sorry for his horses during the conflict, but decided "it is my business to bring every man I can into the presence of the enemy, and to make war short."
Often the fastest way to win a skirmish was to take out the other side's horses. During an encounter in Kentucky on August 30, 1862, Confederate Colonel Benjamin Hill set aside a group of sharpshooters with the sole purpose of "picking off the horses" from the other side.
Horses were also harder to protect on the front lines since they were large targets. At Ream's Station in 1864, Union forces managed to hide behind a barricade, but their 30 horses were unprotected. Minutes later, only two horses remained standing.
Confederate Horses Fared Better Than Union Horses
Horses suffered horrifically during the Civil War, but early in the conflict, Confederate horses generally fared better. That's because Southern cavalrymen rode their own horses to the field. The bond between rider and horse helped horses perform better under fire.
But as the conflict dragged on, both sides struggled to keep their mounts outfitted for skirmishes. Simple tasks like feeding the horses proved problematic. Major General William T. Sherman ordered his troops that "every opportunity at a halt during a march should be taken advantage of to cut grass, wheat, or oats and extraordinary care should be taken of the horses upon which everything depends.”
Horses generally needed around 25 pounds of grain and hay per day, but in the later years of the conflict, many horses went on starvation rations. After horses picked an area clean, troops had to bring in grain. In 1864, some Union artillery horses only received 5 pounds of grain a day.
Providing food for horses was a constant problem for Union and Confederate troops. In 1864, Major William Jennings and his regiment covered over 900 miles in less than five months. Of their 961 horses, 401 perished. Jennings reported, "The majority that [perished or] were abandoned were literally starved."
Caring for horses also required an adequate water supply. When there weren't nearby sources, soldiers would round up half the horses to ride to a river or stream. The other half stayed behind in case the enemy mounted a surprise strike.
When horses were injured during the Civil War, they often didn't receive adequate medical treatment. In the 1860s, there were only six veterinarians total in the military. Instead, soldiers and farriers generally cared for their horses, which sometimes included putting them down.
A Horse Advantage Helped The North Win The Conflict
Even off the front lines, life was difficult for a horse. A lack of food, neglect by troops, and poor medical treatment all contributed to the loss of more than one million horses and mules during the clash.
Men on both sides of the conflict loved and cared for their horses. General Ulysses S. Grant devoted himself to caring for his horse, Cincinnati. According to one story, Grant turned down an offer to buy Cincinnati for $10,000 because he refused to part with his horse. Grant even took Cincinnati to the White House when he became president.
Similarly, Robert E. Lee was inseparable from his horse, Traveller. When the conflict ended, Lee brought Traveller to Washington College, where the horse was so famous that dozens plucked hairs from his tail. Traveller even marched in Lee's funeral procession in 1870.
As General Sherman declared, in the Civil War "everything depends" on the horses.
In fact, horses were vital to the North's victory. As Quartermaster M.C. Meigs argued, "A horse for military service is as much a military supply as a barrel of gunpowder or a shotgun or rifle." And going into the conflict, the North had a major horse advantage.
At the outbreak of the conflict, the North had 3.4 million horses to 1.7 million in the Confederacy. While the Confederacy's mounts were better trained for the cavalry, the Union's supply helped it emerge victorious after years of clashing.
Of the roughly 5 million horses in the United States before the Civil War, over 20% perished during the conflict - a shocking rate much higher than the human toll of roughly 2% of the population.