Though he was known for his compassionate understanding of plight of the Puget Sound Indians, Silas Casey came to the region already experienced in both Indian fighting and military command. A graduate of West Point in 1826, Casey was immediately assigned to frontier duty and had his first battle with Indians in September 1828. His career would take him to Florida to fight against the Seminoles from 1837 to 1842, and to Oregon in 1851 to fight the Coquille Indians.

Lieutenant Colonel Casey arrived in Puget Sound to take command of Fort Steilacoom on January 17, 1856. Hostilities between the Indians and settlers were already fomenting, so the following month he led a force to the White River area, where he dealt a series of defeats to the Indians.

In March 1856, in the last decisive battle of the Puget Sound Indian War, Casey defeated the Indians with a detachment of one hundred ten volunteers. The Indians, broken into smaller bands, were never again able to mount a force powerful enough to do any major damage. Colonel Casey had put the war west of the Cascades to an end.

Although the war with the Indians was over for Colonel Casey, he would find himself torn between the policies of General John E. Wool, Commander of the Department of the Pacific, and Washington Territorial Governor Isaac Stevens. Governor Stevens, who had resigned his Army commission to accept the governorship, was ambitious and aggressive in his dealing with the Indians. His manner toward the Army suggested that of a commander-in-chief. General Wool, a veteran of both the War of 1812 and the Mexican War, with forty four years of military service, was of the opinion that compromise and moderation were necessary in dealing with the Indians. He felt that further hostilities were more likely to be caused by the white settlers than the Indians.

Colonel Casey's own position on dealing with Indians more closely resembled General Wool's than Governor Steven's approach. Stevens wished to launch a winter campaign in 1855-1856 to crush hostile Indians by destroying their livestock and provisions. General Wool wished to proceed more slowly, to evaluate the extent of hostilities and the need for reinforcements in some areas. Stevens wanted to use the volunteer Militia to close the mountain passes, isolating all the Indians for the winter. There were insufficient volunteers to accomplish this task, however, so Stevens tried to force the Army to supplement the Militia. Casey countered by requesting that two companies of Militia be placed with the Army.

Stevens wanted all Indian leaders who had surrendered or been captured to be brought to trial as murderers, whether or not such action might cause renewed hostilities. Colonel Casey supporting the position of Colonel Wright, commander of the Ninth Infantry in eastern Washington Territory, felt such action would be unwise. He preferred the view that they had been at war with the Indians, but now they were at peace. Casey and other Army officers did not wish to see either Indians or soldiers involved in warfare face criminal charges for their wartime actions.

Stevens was especially eager to see Leschi, the Nisqually leader, punished, even though he was an important man and well-regarded by some. Casey countered by offering his support to Leschi. When Leschi offered to surrender himself to the authorities, Casey urged him to go into hiding until the climate was more favorable to negotiation. Casey's good intentions were undone by Sluggia's betrayal of Leschi.

Leschi was captured on November 13, 1856, and his first trial was held three days later. This trial resulted in a hung jury. Following a second trial, Leschi was sentenced in December 1857.

Casey approved the actions of one of his subordinates, Lt. August Kautz, to free Leschi who was being held at Fort Steilacoom. Only when all legal options had been exhausted did Casey finally turn Leschi over to the authorities, and even then, he refused to allow the hanging to occur on Army property.

Casey's policy of moderation and tolerance with regard to the Indians enabled him to convince most of the Puget Sound tribes to pursue a path of peace. Those same policies at times angered the settlers, who hanged him in effigy as they awaited the real hanging of Leschi. When war ended west of the mountains, however, the settlers once again grew to trust the Army, and Colonel Casey, to protect them.

Hemphill, Major General John A. and Robert C. Cumbow. West Pointers and Early Washington: The Contributions of U.S. Military Academy Graduates to the Development of the Washington Territory, from the Oregon Trail to the Civil War, 1834-1862. Seattle: The West Point Society of Puget Sound, Inc., 1992.