The Erastus Beck mercantile ledger was presented to Beck by the Agencia del Timbre de la Ascencion to be used for his mercantile business located in the Colonia Diaz, a Latter Day Saint colony in Mexico. The ledger consists of accounting notations regarding merchandise sold along with a listing of about 250 different buyers of more than a thousand horses. Each of these entries list the buyer, the number of horses, the colors, the brands, and the initials of the clerk.