In 1862, long-standing tensions in the Minnesota River Valley between the Dakota people and the U.S. government erupted into a tragic six-week war after broken treaty promises, delayed money and food payments, land loss, and cultural misunderstandings drove some Dakota warriors to reclaim their homeland. After a council of Dakota leaders met in August, some warriors attacked the Redwood (Lower Sioux) Agency and nearby trader's stores on August 18, beginning fighting that spread across southwestern Minnesota and included major battles at New Ulm, Fort Ridgely, Birch Coulee, and Wood Lake. By the Battle of Wood Lake on September 23, more than 500 settlers, agency employees, traders, soldiers, and others had been killed, along with a smaller, unknown number of Dakota people. Some Dakota surrendered and released captives, while others were captured by soldiers, and a field military court condemned more than 300 Dakota men to death; 38 were eventually hanged and the rest were sent to a prison in Iowa, where many did not survive the journey or their three-year sentence. The war permanently changed life along the Minnesota River: a small number of Dakota who had assisted the government were allowed to stay, but almost all were forced from their homeland, and many who had not fought were taken to a concentration camp at Fort Snelling, where hundreds died during the winter of 1862-63 before most survivors were moved to Crow Creek in what is now South Dakota. The state government also paid a bounty for any unauthorized Dakota person remaining in Minnesota. Some exiled Dakota later returned, but many families were permanently broken apart, while among immigrant settlers who had fled during the fighting, some returned home and others never did. The conflict also had effects beyond Minnesota, leading to further battles farther west as indigenous people fought to retain their homelands and way of life.