It's easy to forget that most Confederate officers were pardoned after the war, either en masse for rebellion or individually if they were accused of other crimes, and returned to lives of business or started new careers in politics. Relatively few of them would see combat in the American-Indian Wars. But one famous general offered his skills to America during the Spanish-American War and led all cavalry units in Cuba, including Theodore Roosevelt's Rough Riders and Buffalo Soldiers.
Joseph "Fighting Joe" Wheeler got his start as a graduate of the U.S. Military Academy at West Point in 1859 and was sent west to fight Native Americans. But the Civil War broke out in 1861, and then-2nd Lt. Wheeler resigned his U.S. commission and joined the Confederacy.
And the Confederacy was trying to stand up a national military, from scratch, to defend itself. So state militia officers and former U.S. Army officers with good training saw themselves quickly promoted. Wheeler became a colonel of infantry, then the head cavalry officer for the Army of Mississippi. By the end of the war, he was a lieutenant general.
During the conflict, Wheeler made a name for himself as a fighter. At one point in 1863, he conducted a stunning raid against Union Maj. Gen. William S. Rosencrans. Rosencrans was under firm orders to hold Chattanooga, but all of his beans and bullets had to pass down 100 miles of rail and 60 miles of mountain paths. His force was nearly encircled and so low on vital supplies that soldiers were on half rations and had enough ammo for only one day of fighting.
Wheeler took advantage of this. Despite having his own shortage of battle-ready men and horses, he took on a mission to conduct a massive raid against Rosencrans. He hand-picked what men and horses were ready to fight and took them out from Oct. 1-9, 1863. They cut through the Union lines, destroyed hundreds of Union wagons, and choked off Rosencrans.
But battles like the Great Sequatchie Valley Raid made Wheeler a hero to the Confederacy and a villain to the Union, and the end of the war saw Wheeler out on his butt. But he embraced the reality post-war and ran for office in Alabama, serving for years in Congress as a leader of North-South reconciliation.
When the Spanish-American War started in 1898, Wheeler was 61-years-old, but he offered his services as a military leader to the Army and was accepted. He left the House of Representatives and shipped to Cuba.
While he wasn't the only former Confederate to fight in Cuba, he does seem to be the only former Confederate general to serve as a general for the U.S. Army in combat after the war. In Cuba, he commanded all cavalry forces; even the famed Rough Riders put together by former Assistant Secretary of the Navy and future President Theodore Roosevelt.
As a Maj. Gen. of Volunteers, Wheeler led his men against Spanish troops at Las Guasimas, participated in the Battle of San Juan Hill, and then fought at the siege of Santiago in Cuba. He was even placed over the 9th and 10th cavalry regiments, Buffalo Soldier units.
He performed well enough that, despite his age, he was offered a commission in the regular Army as a brigadier general and led troops in the Philippine-American War. While he wasn't often fighting on the front lines, the brigadier general was still competent and valuable as a battlefield leader.