Fort Bridger was established by mountain man Jim Bridger in 1843. It originally served as a trading post for emigrants traveling the Oregon Trail. However, when alternate routes were discovered, the fort was largely abandoned. In 1853, Bridger sold the fort to the Mormons, who burned it during the Utah War in 1857, following conflicts with the federal government.

In 1862, the U.S. Army occupied Fort Bridger, using it as a headquarters from which to combat Indian raids. During the Civil War, soldiers stationed in the West were charged with the important role of protecting the overland mail routes, which often supplied silver to finance the Union efforts. Fort Bridger continued as an active military post into the 1880s, as well as serving as Pony Express and Overland Stage outposts.

It is probable that Robert Schiller was the creator of this ledger; however, that assumption is not independently verifiable. Although it is not clear who employed the creator of this ledger, the waybills indicate that many of his passengers were military officers. A waybill is a receipt given by a mail carrier to the shipper acknowledging receipt of the goods and specifying the shipment details, route, and charges. This mail carrier transported goods and escorted people to various cities between California and Kansas, while Fort Bridger served as his headquarters.