Fort Ridgely was a United States military post established in 1853. On August 18-27, 1862, soldiers, citizens, and refugees successfully defended it through nine days of siege and investment, including two formidable and protracted assaults on August 20 and 22 by a vastly superior force of Sioux Indians under Little Crow and other leaders and warriors. On August 18, 1862, Sioux Indians of the Upper Minnesota River, in violation of their treaties, broke into open rebellion and within a few days massacred about one thousand citizens in the southwestern part of Minnesota and destroyed property worth millions of dollars. Many men, women, and children fled to Fort Ridgely and remained under its protection during the siege. The successful defense by parts of Companies B and C of the Fifth Regiment Minnesota Volunteer Infantry, the Renville Rangers, and citizens and refugees was very largely instrumental in saving other portions of Minnesota from ravage and devastation and greatly contributed to the ultimate defeat of the Indians and their expulsion from the state. During the entire siege, the garrison was skillfully commanded by Lieutenant Timothy J. Sheehan of Company C, Fifth Regiment, Minnesota Infantry, assisted by Lieutenant Norman K. Culver, Lieutenant Thos. P. Gere, Lieutenant James Gorman, Benj. H. Randall, Ordnance Sergeant John Jones, Sergeant James G. McGrew, John C. Whipple, and Doctor Alfred Muller. Captain John F. Marsh, twenty-three men of Company B, and U.S. interpreter Peter Quinn had been killed by the Indians at Redwood Ferry on August 18, 1862. A number of women also cheerfully and bravely assisted in the defense of the fort, and other citizens rendered valuable services.