Along the frontier of struggle campaigns of this sort occurred from time to time, receiving little attention from the authorities who were directing weightier movements at the centre. Less formal than these, and more provocative of bitter feeling, were the attacks of guerrillas along the central frontier,—chiefly the Missouri border and eastern Kansas. Here the passions of the struggle for Kansas had not entirely cooled down, southern sympathizers were easily found, and communities divided among themselves were the more intense in their animosities.

The Department of Kansas, where the most aggravated of these guerrilla conflicts occurred, was organized in November, 1861, under Major-general Hunter. From his headquarters at Leavenworth the commanding officer directed the affairs of Kansas, Nebraska, Dakota, Colorado, and "the Indian Territory west of Arkansas." The department was often shifted and reshaped to meet the needs of the frontier. A year later the Department of the Northwest was cut away from it, after the Sioux outbreak, its own name was changed to Missouri, and the states of Missouri and Arkansas were added to it. Still later it was modified again. But here throughout the war continued the troubles produced by the mixture of frontier and farm-lands, partisan whites and Indians.

Bushwhacking, a composite of private murder and public attack, troubled the Kansas frontier from an early period of the war. It was easily aroused because of public animosities, and difficult to suppress because its participating parties retired quickly into the body of peace-professing citizens. In it, asserted General Order No. 13, of June 26, 1862, "rebel fiends lay in wait for their prey to assassinate Union soldiers and citizens; it is therefore ... especially directed that whenever any of this class of offenders shall be captured, they shall not be treated as prisoners of war but be summarily tried by drumhead court-martial, and if proved guilty, be executed ... on the spot."

In August, 1863, occurred Quantrill's notable raid into Kansas to terrify the border which was already harassed enough. The old border hatred between Kansas and Missouri had been intensified by the "murders, robberies, and arson" which had characterized the irregular warfare carried on by both sides. In western Missouri, loyal unionists were not safe outside the federal lines; here the guerrillas came and went at pleasure; and here, about August 18, Quantrill assembled a band of some three hundred men for a foray into Kansas. On the 20th he entered Kansas, heading at once for Lawrence, which he surprised on the 21st. Although the city arsenal contained plenty of arms and the town could have mustered 500 men on "half an hour's notice," the guerrilla band met no resistance. It "robbed most of the stores and banks, and burned one hundred and eighty-five buildings, including one-fourth of the private residences and nearly all of the business houses of the town, and, with circumstances of the most fiendish atrocity, murdered 140 unarmed men." The retreat of Quantrill was followed by a vigorous federal pursuit and a partial devastation of the adjacent Missouri counties. Kansas, indignant, was in arms at once, protesting directly to President Lincoln of the "imbecility and incapacity" of Major-general John M. Schofield, commanding the Department of the Missouri, "whose policy has opened Kansas to invasion and butchery." Instead of carrying out an unimpeded pursuit of the guerrillas, Schofield had to devote his strength to keeping the state of Kansas from declaring war against and wreaking indiscriminate vengeance upon the state of Missouri. A year after Quantrill's raid came Price's Missouri expedition, with its pitched battles near Kansas City and Westport, and its pursuit through southern Missouri, where confederate sympathizers and the partisan politics of this presidential year made punitive campaigns anything but easy.

Carleton's march into New Mexico has already been described in connection with the mining boom of Arizona. The silver mines of the Santa Cruz Valley had drawn American population to Tubac and Tucson several years before the war; while the confederate successes in the upper Rio Grande in the summer of 1861 had compelled federal evacuation of the district. Colonel E. R. S. Canby devoted the small force at his command to regaining the country around Albuquerque and Santa Fé, while the relief of the forts between the Rio Grande and the Colorado was intrusted to Carleton's California Column. After May, 1862, Carleton was firmly established in Tucson, and later he was given command of the whole Department of New Mexico. Of fighting with the confederates there was almost none. He prosecuted, instead, Apache and Navaho wars, and exploited the new gold fields which were now found. In much of the West, as in his New Mexico, occasional ebullitions of confederate sympathizers occurred, but the military task of the commanders was easy.

The military problem of the plains was one of police, with the extinction of guerrilla warfare and the pacification of Indians as its chief elements. The careers of Canby, Carleton, and Gilpin indicate the nature of the western strategic warfare, Schofield's illustrates that of guerrilla fighting, the Minnesota outbreak that of the Indian relations.

In the Northwest, where the agricultural expansion of the fifties had worked so great changes, the pressure on the tribes had steadily increased. In 1851 the Sioux bands had ceded most of their territory in Minnesota, and had agreed upon a reduced reserve in the St. Peter's, or Minnesota, Valley. But the terms of this treaty had been delayed in enforcement, while bad management on the part of the United States and the habitual frontier disregard of Indian rights created tense feelings, which might break loose at any time. No single grievance of the Indians caused more trouble than that over traders' claims. The improvident savages bought largely of the traders, on credit, at extortionate prices. The traders could afford the risk because when treaties of cession were made, their influence was generally able to get inserted in the treaty a clause for satisfying claims against individuals out of the tribal funds before these were handed over to the savages. The memory of the savage was short, and when he found that his allowance, the price for his lands, had gone into the traders' pockets, he could not realize that it had gone to pay his debts, but felt, somehow, defrauded. The answer would have been to prevent trade with the Indians on credit. But the traders' influence at Washington was great. It would be an interesting study to investigate the connection between traders' bills and agitation for new cessions, since the latter generally meant satisfaction of the former.

Among the Sioux there were factional feelings that had aroused the apprehensions of their agents before the war broke out. The "blanket" Indians continually mocked at the "farmers" who took kindly to the efforts of the United States for their agricultural civilization. There was civil strife among the progressives and irreconcilables which made it difficult to say what was the disposition of the whole nation. The condition was so unstable that an accidental row, culminating in the murder of five whites at Acton, in Meeker County, brought down the most serious Indian massacre the frontier had yet seen.

There was no more occasion for a general uprising in 1862 than there had been for several years. The wiser Indians realized the futility of such a course. Yet Little Crow, inclined though he was to peace, fell in with the radicals as the tribe discussed their policy; and he determined that since a massacre had been commenced they had best make it as thorough as possible. Retribution was certain whether they continued war or not, and the farmer Indians were unlikely to be distinguished from the blankets by angry frontiersmen. The attack fell first upon the stores at the lower agency, twenty miles above Fort Ridgely, whence refugee whites fled to Fort Ridgely with news of the outbreak. All day, on the 18th of August, massacres occurred along the St. Peter's, from near New Ulm to the Yellow Medicine River. The incidents of Indian war were all there, in surprise, slaughter of women and children, mutilation and torture.

The next day, Tuesday the 19th, the increasing bands fell upon the rambling village of New Ulm, twenty-eight miles above Mankato, where fugitives had gathered and where Judge Charles E. Flandrau hastily organized a garrison for defence. He had been at St. Peter's when the news arrived, and had led a relief band through the drenching rain, reaching New Ulm in the evening. On Wednesday afternoon Little Crow, his band still growing—the Sioux could muster some 1300 warriors—surprised Fort Ridgely, though with no success. On Thursday he renewed the attack with a force now dwindling because of individual plundering expeditions which drew his men to various parts of the neighboring country. On Friday he attacked once more.