To the Senate and House of Representatives:
By recent information received from official and other sources I am advised that an alarming state of disorder continues to exist within the Territory of Arizona, and that lawlessness has already gained such head there as to require a resort to extraordinary means to repress it.
The governor of the Territory, under date of the 31st ultimo, reports that violence and anarchy prevail, particularly in Cochise County and along the Mexican border; that robbery, murder, and resistance to law have become so common as to cease causing surprise, and that the people are greatly intimidated and losing confidence in the protection of the law. I transmit his communication herewith and call especial attention thereto.
In a telegram from the General of the Army dated at Tucson, Ariz., on the 11th instant, herewith transmitted, that officer states that he hears of lawlessness and disorders which seem well attested, and that the civil officers have not sufficient force to make arrests and hold the prisoners for trial or punish them when convicted.
Much of this disorder is caused by armed bands of desperadoes known as "Cowboys," by whom depredations are not only committed within the Territory, but it is alleged predatory incursions are made therefrom into Mexico. In my message to Congress at the beginning of the present session I called attention to the existence of these bands and suggested that the setting on foot within our own territory of brigandage and armed marauding expeditions against friendly nations and their citizens be made punishable as an offense against the United States. I renew this suggestion.
To effectually repress the lawlessness prevailing within the Territory a prompt execution of the process of the courts and vigorous enforcement of the laws against offenders are needed. This the civil authorities there are unable to do without the aid of other means and forces than they can now avail themselves of. To meet the present exigencies the governor asks that provision be made by Congress to enable him to employ and maintain temporarily a volunteer militia force to aid the civil authorities, the members of which force to be invested with the same powers and authority as are conferred by the laws of the Territory upon peace officers thereof.
On the ground of economy as well as effectiveness, however, it appears to me to be more advisable to permit the cooperation with the civil authorities of a part of the Army as a posse comitatus. Believing that this, in addition to such use of the Army as may be made under the powers already conferred by section 5298, Revised Statutes, would be adequate to secure the accomplishment of the ends in view, I again call the attention of Congress to the expediency of so amending section 15 of the act of June 18, 1878, chapter 263, as to allow the military forces to be employed as a posse comitatus to assist the civil authorities within a Territory to execute the laws therein. This use of the Army, as I have in my former message observed, would not seem to be within the alleged evil against which that legislation was aimed.
CHESTER A. ARTHUR
Chester A. Arthur, Special Message Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/204294