Fort Croghan, a United States military post, was established at the site of a frontier post known as McCulloch's Station, on Hamilton Creek three miles south of the site of present Burnet in Burnet County. Henry E. McCulloch and his rangers were stationed there when the place was chosen for the fort on March 13, 1849, by Lt. C. H. Tyler, commander of Company A of the Second Dragoons. McCulloch was not relieved of his duty until March 18, when the site became officially a federal post. On October 12 a new location was chosen, and the fort was built across Hamilton Creek three miles above the first site. The post was known as Camp Croghan, then Camp Hamilton, and finally as Fort Croghan, in honor of Col. George Croghan. The buildings were of oak covered with shingles; officers' quarters were four log houses, each with two rooms separated by a hall. The hospital was a large four-room log house. The fort became headquarters of the Second Dragoons in 1852, but the government started removing its troops in 1853, and only a small guard remained when orders were issued to abandon the fort in 1855. The buildings were used as residences; the old hospital, long the home of W. P. Fry, was torn down in 1922. In 1940 only the foundations remained as evidence of the military occupation.
During the late 1950s and early 1960s the Burnet County Historical Society began the reconstruction of Fort Croghan. Since all original buildings had been destroyed, old buildings in the area that had been built at the time of the fort were moved from their original locations to the site. They included typical frontier log houses and one stone building that had been one of the original homes of Hamilton valley. Descendants of the first settlers in the area contributed authentic nineteenth-century articles to furnish the relocated buildings. By 1967 three buildings had been completely restored and were open to the public from April to November. The society in that year was also in the process of restoring a store building.