Before the invention of barbed wire cattle roamed freely over the open range. It was therefore necessary for the owner to burn an identifying mark on the hides of his livestock. This was done with a hot branding iron. Brands were formed from numbers, letters and symbols. These brands were then registered in the official county brand book.

Some cowboys made a living from stealing unbranded cattle. These men, called rustlers, also took marked cattle and altered the legitimate brand with a hot iron. Rustlers were much hated by ranchers and were often killed or lynched without reference to the law.

Primary Sources

(1) William Cullen Bryant, Letters of a Traveller (1851)

Horse-thieves are numerous in this part of the country. A great number of horses are bred here; you see large herds of them feeding in the open prairies, and at this season of the year every full-grown mare has a colt running by her side. Most of the thefts are committed early in the spring, when the grass begins to shoot, and the horses are turned out on the prairies, and the thieves, having had little or no employment during the winter, are needy; or else in the autumn, when the animals are kept near the dwellings of their owners to be fed with Indian corn and are in excellent order. The thieves select the best from the drove, and these are passed from one station to another till they arrive at some distant market where they are sold. It is said that they have their regular lines of communication from Wisconsin to St. Louis, and from the Wabash to the Mississippi. In Ogle county they seem to have been bolder than elsewhere, and more successful, notwithstanding the notoriety of their crimes, in avoiding punishment. The impossibility of punishing them by process of law, the burning of the court-house at Oregon City last April, and the threats of deadly vengeance thrown out by them against such as should attempt to bring them to justice, led to the formation of a company of citizens, "regulators" they call themselves, who resolved to take the law into their own hands and drive the felons from the neighborhood. This is not the first instance of the kind which has happened in Illinois. Some twenty years since the southern counties contained a gang of horse-thieves, so numerous and well-organized as to defy punishment by legal means, and they were expelled by the same method which is now adopted in Ogle county.