Later, Culbertson and his wife Natawista Iksina negotiated with the Blackfoot Confederacy to let the northern Pacific railroad survey of 1853 continue unharmed.

[1] He left the family home in 1826, when he followed his uncle, John Craighead Culbertson, a sutler with the army, to Florida.

[2] In 1827, he came to St. Louis where he made his first contacts with John Jacob Astor's American Fur Company, then managed by Pierre Chouteau, Jr.

[3] In 1833, Culbertson returned to St. Louis and signed a three-year contract with the American Fur Company, beginning work as a clerk.

[10] Later he and his wife persuaded the Blackfoot Confederacy to let the northern Pacific railroad survey of 1853, under Isaac I. Stevens, continue unharmed.

[14] Culbertson died in 1879, at the home of his son-in-law, George H. Roberts, Attorney General of Nebraska, who was married to his oldest daughter, Julia.