A battle unfolded out West 150 years ago this week during the Civil War.

On March 26, 1862, a Confederate force of about 300 Texas fighters camped near Glorieta Pass in New Mexico Territory — a strategic location at the southernmost end of the Sangre de Cristo Mountains on the Santa Fe trail.

Several hundred approaching Union soldiers led by Maj. John M. Chivington went on the attack, pressing in on the Confederates until artillery fire threw the federal fighters back. Chivington split his force into two groups on each side of the pass and put the rebels in a cross-fire before fighting halted for the day.

The next day, both sides regrouped and fighting wouldn’t resume again until March 28, 1862, with the Union side swelled by hundreds of reinforcements. Confederates held their ground as the battle surged back and forth in the coming hours.

Eventually a wearied Confederate force retreated to Santa Fe — and eventually back to Texas — securing a strategic Union victory in a key point of the conflict out West.

Elsewhere, Union Gen. George B. McClellan has begun a longawaited step of moving thousands of troops, heavy artillery, armaments and supplies to Fort Monroe off Virginia as he prepares for a major federal assault on Richmond, capital of the Confederacy. For weeks and even months, McClellan had come under criticism for not waging an all- out offensive sooner. But now he was on the move.

Nonetheless, the Springfield Daily Republican in Massachusetts indicates McClellan had already lost some element of surprise ahead of what would be his ill-fated Virginia peninsula campaign. A dispatch in the paper reported: “ The latest accounts from Richmond show that the rebels are crowding troops down upon the York and James River, showing they know where to expect Gen. McClellan.”