Scouts Out! Cavalry Ho!
Not that you'd know it, but there's a lot more to the history of the Cav than the Indian Wars. You do realize that there's still Cavalry in the US Army, don't you? And that they don't ride horses anymore? You do realize that the Cavalry existed long before the 1870s, don't you? Maybe that's a big assumption in your case...
Scouts Out! Cavalry Ho!