In August 1868, General Philip Sheridan replaced Hancock in command of the Department of the Missouri and was asked by acting Governor Frank Hall of Colorado for assistance after 79 settlers were killed in repeated attacks on farms, ranches, way stations, and travel routes. Sheridan's main effort was to be made south of the Arkansas during a winter campaign in the Indian Territory, but he remained active in Kansas during the warmer weather, patrolling the Arkansas with the 7th Cavalry and the area between the Republican and Smoky Hill Rivers using the 10th Cavalry.