In the decades prior to the US Civil War, escaped slaves were quite a problem for those living in the southern United States. Slave owners would place ads for runaway slaves in their local newspapers, making it clear that they wanted their human property back. There were laws against helping a fugitive slave, including the Fugitive Slave Laws of 1793 and 1850, which stated that law enforcement could intervene and help slave owners retrieve their property. Slave catchers were sometimes hired to spread the word by posting wanted posters for escaped slaves around free (non slave-holding) states, and by physically transporting any runaway slaves that were captured. Abolitionists running Underground Railroad stops were constantly on the lookout for these slave catchers.
The ads for escaped slaves tended to consist of several important details: a description of the slave, a reward for their capture and safe return, and an address of the plantation or farm from which the slave had escaped. In some cases, these wanted posters for runaway slaves would contain a sketch of the slave (this was before photography was invented, in some cases, or at least before it was widespread), but this was not common. In modern times, it's shocking to see how these runaway slaves were described.
(Note: When reading these ads, please remember that in the late 1700s and early 1800s, the letter "f" sometimes stood in for the letter "s." Knowing this will make these ads easier to read and understand. This practice dates back hundreds of years, and was still in practice during the early colonial period.)