Some people—they tend to look upon mere stamp collectors with disdain—collect interesting envelopes; for example, those sent to or from persons of consequence. To such a collector the envelope reproduced below would probably bring a high fever of excitement. It was sent in June, 1847, from a famous United States senator who was a giant in the annals of the opening of the West, to his equally famous explorer-soldier son-in-law—and sent in care of a third man whose name has become as legendary as Davy Crockett’s. Thomas Hart Benton, Missouri’s first senator and still considered one of her greatest, was a big man physically, mentally, and politically. He never flagged in his determination to see the American nation reach out to embrace Oregon, California, and the vast Southwest. When his daughter Jessie eloped in 1841 with a handsome and dynamic young army lieutenant named John Charles Frémont, Senator Benton was soon reconciled by the ardor with which Frémont conducted several important exploring expeditions westward. One of them ended, in 1846, with action against the Mexicans at Sonoma and the first raising of California’s Bear Flag as the ensign of independence from Mexico. Christopher “Kit” Carson was Frémont’s chief guide on that expedition and on others; as a result of Frémont’s enthusiastic reports, his name too became an exciting one for stay-at-home Americans. By June of 1847, Frémont was in trouble, having quarrelled with tough old Stephen Watts Kearny, the conqueror of California—in fact, he was on his way east to face a court-martial for insubordination. (Frémont was convicted—unjustly, many thought; he remained famous and popular.) Senator Benton. tremendously vague as to his son-in-law’s exact whereabouts, addressed a letter on June 22, 1847, from Fort Leavenworth (then in Missouri) to “Lt. Col. Frémont, New Mexico, or California” assuring him that his family was well and eagerly awaiting his return. As an afterthought and in view of the uncertainties of mail service on the wild frontier, the Senator added: “Care of Mr. C. Carson.” It was a very primitive zip code, but apparently effective: the letter eventually reached the addressee. It now reposes in the Southwest Museum in Los Angeles.