Complex sentence: Due to the violent armed conflicts in Westport and the surrounding area during the Civil War, she moved east, first to Ste. Genevieve, Missouri, then to Kaskaskia, remaining there until 1867 when she returned to Kansas City with her son Pierre and his wife.
Split into simpler sentences: Due to the violent armed conflicts in Westport and the surrounding area during the Civil War, she moved east, first to Ste. Genevieve, Missouri, then to Kaskaskia. Two years after the end of the war, in 1867, she returned to Kansas City with her son Pierre Chouteau and his wife.