Battle of Glorieta Pass

 

(Wikipedia) The Battle of Glorieta Pass, fought from March 26 to 28, 1862 in northern New Mexico Territory, was the decisive battle of the New Mexico Campaign during the American Civil War.
... it was intended as the killer blow by Confederate forces to break the Union possession of the West along the base of the Rocky Mountains.
It was fought at Glorieta Pass in the Sangre de Cristo Mountains in what is now New Mexico, and was an important event in the history of the New Mexico Territory in the American Civil War. Continued