Fort Duncan was founded on March 27, 1849 by Army Captain Sidney Burbank. Transferred there were three companies of the 1st United States Infantry. It was situated on the Rio Grande River. Later in the year 1849, he post was named Fort Duncan, after Col. James Duncan, a hero of the Mexican–American War.
Fort Clark was one of the longest forts to be in service in Texas. It was founded in 1852 and not finally closed or abandoned until 1946. It was considered a favorable location due to having a plentiful water supply from the Las Moras River and its close proximity to Las Moras Mountain. It served two major purposes, to protect the area against Indian raids and to protect its portion of the military road from San Antonio to El Paso. Companies C and E of the the First United States Infantry were posted there. It was named for Major John B. Clark who died in 1847 during the Mexican-American War.
Fort Mason was established and vacated before the Civil War. It was set up by Brevet Lt. Col. W. H. Harvey in the summer of 1851 and housed the Second Dragoons. It was named for Second Lt. George T. Mason of the Second Dragoons, killed during the early days of the Mexican-American War in South Texas in 1846. It has also been suggested that the fort could have been named for General Richard Barnes Mason who had died more recently, but most sources favor George T. Mason, a West Point graduate and native of Virginia.
Fort Fisher, as it was known, was set up for a short time on the west bank of the Brazos river near the settlements that would give rise to Waco. It was established by the Texas Rangers to provide security for settlers in 1837 and to the best of our knowledge, it was also abandoned the same year. The outpost was named for William S. Fisher, Secretary of War of the Republic of Texas at the time. Fisher was a long time member of the Texas Army. He would later become a participant in the ill fated Mier Expedition after which he would be captured and imprisoned in Mexico. Fisher passed away around two years after being released from his confinement in Mexico.
Fort McKavett is located near Menard in Menard County, Texas. It was one in a line of Texas frontier forts built during the era to protect settlers who were moving into the area. The forts were situated roughly in a diagonal line connecting the Red River to the Rio Grande and about one hundred miles west of the currently occupied land at the time. United States Army infantry colonel Thomas Staniford was given orders to build a military post at the headwaters of the San Saba River and he arrived with his regiment on March 14, 1852. The headwaters were a natural spring and Staniford decided to move the location about two miles down from it where the spring formed a small lagoon, favoring the water supply there.