Letter of Instructions from W.L. MARCY, Secretary of War, to Brigadier General S.W. KEARNY, commanding United States forces at Fort Leavenworth, dated June 3, 1846 War Department, Washington.

“… It has been decided by the President to be of the greatest importance, in the pending war with Mexico, to take early possession of Upper California. An expedition, with that view, is hereby ordered, and you are designated to command it.” …………. “It is known that a large body of Mormon emigrants are enroute to California, for the purpose of settling in that country. You are desired to use all proper means to have a good understanding with them, to the end that the United States may have their cooperation in taking possession of and holding that country. It has been suggested here, that many of these Mormons would willingly enter into the service of the United States, and aid us in our expedition against California. You are hereby authorized to muster into service such as can be induced to volunteer, not, however to a number exceeding one-third of your entire force. Should they enter the service, they will be paid as other volunteers, and you can allow them to designate, as far as it can properly be done, the persons to act as their officers. It is understood that a considerable number of American citizens are now settled on the Sacramento River, near Suter’s establishment, called Nueva Helvetica …..”

** The additional inducement was offered the Mormons that, upon the expiration of their term of service, they would be allowed to retain as their private property the guns and accoutrements furnished them by the government. **