The Rough Riders was a nickname given to the 1st United States Volunteer Cavalry, one of three such regiments raised in 1898 for the Spanish–American War and the only one of the three to see action. The United States Army was small and understaffed in comparison to its status during the American Civil War roughly thirty years prior. As a measure towards rectifying this situation President William McKinley called upon 125,000 volunteers to assist in the war efforts. The regiment was also called "Wood's Weary Walkers" in honor of its first commander, Colonel Leonard Wood. This nickname served to acknowledge that despite being a cavalry unit they ended up fighting on foot as infantry.

Wood's second in command was former Assistant Secretary of the Navy, Theodore Roosevelt, a man who had pushed for American involvement in the Cuban War of Independence. When Colonel Wood became commander of the 2nd Cavalry Brigade, the Rough Riders then became "Roosevelt's Rough Riders." That term was familiar in 1898, from Buffalo Bill who called his famous western show "Buffalo Bill's Wild West and Congress of Rough Riders of the World." The Rough Riders were mostly made of college athletes, cowboys, ranchers, miners, and other outdoorsmen. With these men being from southwestern ranch country, they were quite skilled in horsemanship.