The Star Fort at Fort Union, New Mexico
Fort Union stood where the Santa Fe Trail came down onto the plains of northeastern New Mexico. It was founded in 1851 and was the Army's main supply depot for the Southwest. In 1861, as Confederate Texans started up the Rio Grande, the commander judged that the old log buildings couldn't be defended, and he put his men to digging.
What they built was an earthwork shaped like an eight-pointed star. It had bastions placed so cannon could cover every approach, along with ditches and bombproof shelters set into the ground. The work was rushed through in the second half of 1861. Living in it was miserable. It was damp and cramped, and the walls soon began to crumble. Work on it stopped in June 1862, and in 1863 the Army began a third, adobe Fort Union close by.
The road to Glorieta Pass
No cannon in the star fort was ever fired at an enemy. It mattered anyway. In March 1862 Colorado volunteers came south through Fort Union on the way to Glorieta Pass, where they helped stop the Confederate push toward the depot. After the war the third Fort Union grew into the largest military post in the region. The railroad eventually made the trail obsolete, and the Army left in 1891.
Visitors to Fort Union National Monument, near Watrous, can still see the outline of the star earthwork on the ground.
West of the War tells the story of the New Mexico campaign that the star fort was built to stop.
Sources: National Park Service, Fort Union National Monument (nps.gov/foun), including "The Star Fort"; Robert M. Utley, Fort Union National Monument (NPS Historical Handbook Series No. 35).
Illustration: AI-generated, artistic interpretation.