The fort originally covered some 50 acres (20 ha) near the present-day city of Burnet, Texas, extending from Hamilton Creek up and over Post Mountain.

Today, a small section exists due to the efforts of the Burnet County Historical Society, which raised money in the 1960s to purchase this portion of the old fort.

[1] In the 1840s, upon the annexation of Texas to the United States, the federal government became responsible for the protection of frontier settlers from Indian raids.

In December 1847, a company of Rangers under the command of Henry Eustace McCulloch took up a position about 3 miles (5 km) south of present-day Burnet.

[2] The indigenous peoples of the Americas had occupied this region for thousands of years, but did not build or live in permanent homes, theirs being a migratory culture.

Indians who had been peaceful due to treaties and the presence of the United States soldiers during the U.S.-Mexican War now began to come into conflict with these newcomers.

Burnet County's first white resident, Sam Holland, objected strenuously to a military post being located near his home.

Early presidents of the Burnet County Historical Society included Rethie Dorbandt, Ed Young, Virgil Lewis, Tad Moses, Jimsey Husted, Phyllis Adrian, Reta Ross, Clyde Mather, Mrs. T.D.

[1] The Fort Croghan Museum features historical artifacts including tools, household items, and Western gear.