Back then the post consisted of a storehouse, two magazines, four officers' quarters, and a stone hospital, in addition to quarters for enlisted men. The fort was significant because of the trade crossing into Mexico at Eagle Pass, its location on the California Road, and its position for scouting against Indians in the 1850s.

   History records show that the establishment of Fort Duncan brought an increase of traffic through the area, leading to the settling and establishing of Eagle Pass In 1850. 

    Records further state that Fort Duncan was involved in the 1855 James H. Callahan expedition which led an effort to repel attacks of Lipan Apache Indians, and to capture runaway slaves that ended in seizure and the burning down of Piedras Negras.

  Fort commanders then refused to help Callahan cross back into the United States.

   In May, 1859, the fort was abandoned and the troops transferred to Camp Verde, but was later re-established . In 1916 during World War I, the number of troops was increased to 16,000 by 1920, the number had been reduced once again. 

   By 1933, the fort had again been closed down, and eventually the City of Eagle Pass was allowed to develop and maintain the old post as a public park. 

  Now called Fort Duncan Park, the site was listed in the National Register of Historic Places in 1971.  The City of Eagle Pass continues maintaining the area and in recent years have concentrated efforts in embracing the history of Eagle Pass including the Fort Duncan Park area and its historical significance.