I have a letter written June 13, 1862 Springfield, Mo. by Alfred Mosley, Col Kings 3rd Cav regt Mo S. M Co. B. Below is a quote from the letter and I (not being from MO) am confused as to where Neosha is. Also, was it common for Indians to fight in the Civil War as the reference indicates? Does anyone know what tribe the Indians would have belonged to?

Appreciate any help.
Colleen

"about two hundred and 50 of our men was down at neosha and about a thousand Secesh mostly Indians got a fowl of them and bresed them up right nicely Thier hidious yells Scared the federals Horses so they could not keep them any where in order but I guess if we get out there among them their yelling won’t scare our big rifle Canon much"