Fort Duncan Fort Duncan was a United States Army post , set up to protect the first U . S . settlement on the Rio Grande near the current town of Eagle Pass , Texas . Fort Duncan was established on March 27 , 1849 , when Captain Sidney Burbank occupied the site with companies A , B , and F of the First United States Infantry . On November 14 , 1849 , the post was named Fort Duncan , after James Duncan , a hero of the Mexican - American War . The post consisted of a storehouse , two magazines , four officers ' quarters , and a stone hospital , in addition to quarters for enlisted men . Construction was done half by the troops and half by hired workers . There was ample stone but no timber for building , and the men suffered from exposure . Company C , 1st Regiment of Artillery , asked permission to construct quarters at its own expense . During the 1850s , Fort Duncan provided merchants and traders protection from border frontier outlaws and Native Americans . The fort also served as a post for scouting Native Americans . Fort Duncan became involved in the Callahan expedition of 1855 , when James H . Callahan led an effort to repel attacks of Lipan Apache s and to capture runaway slaves . Callahan seized and set Piedras Negras on fire , and the commanders at the fort ultimately refused to help him recross the Rio Grande into the United States . Secretary of War John B . Floyd ordered the post abandoned in May 1859 . Robert E . Lee ordered the fort regarrisoned in March 1860 . With the outbreak of the American Civil War the post was again abandoned when the Federal troops evacuated on March 20 , 1861 . It was also an important customs point for Confederate cotton and munitions trade with Mexico . Federal troops reoccupied Fort Duncan on March 23 , 1868 . During the 1870s , the Seminole Indians became members of the command and were used as guides in the area . Buffalo soldier s were also stationed at Fort Duncan , including George B . Jackson , later a businessman in San Angelo called " the wealthiest black man in Texas " during the second half of the 19th century . The post was abandoned once again in 1883 . From 1890 to 1916 , when disturbances in Mexico took national guard units to the river , the fort had a skeleton caretaking detachment . Troop activity continued throughout World War I , when the fort served as a training facility , but by 1920 only a small detail remained . In 1933 , the City of Eagle Pass began maintaining the old fort as a public park . The city formally acquired the property in 1935 and converted it into Fort Duncan Park . In 1942 the mayor offered the fort to the military for use during World War II . The government used the Fort Duncan Country Club as an officers ' club and the swimming pool for commissioned personnel stationed at Eagle Pass Army Air Field . The site was listed in the National Register of Historic Places in 1971 . Seven of the original buildings still stand today . In the early 1980s , the Fort Duncan Country Club caught fire and only the outer walls remain . The Commander ' s Headquarters building has been converted into the Fort Duncan Museum , with exhibits of local and fort history and artifacts .