Frederick Douglass

Frederick Douglass had many issues with the system of slavery that existed in the United States during the 1800's. Perhaps the greatest qualm he had towards slavery was the treatment of human beings by fellow human beings. While reading his work, "Narrative of the Life of Frederick Douglass, An American Slave, Written by Himself," it was apparent that he greatly disapproved with the treatment of slaves.
Right away in the first chapter, Douglass shares stories of slave owners abusing their workers. He writes, "And it is worthy of remark that such slaves invariably suffer greater hardships, and have more to contend with, than others...she [the slaveowner] is never better pleased than when she sees them under the lash." For the slaves, it was their norm to be abused, and this abuse often was a result of the owner's desire to show their power rather than an actual reason for inducing pain.
As Douglass transitions from being a slave on a plantation to a slave in Baltimore, he finds differences in the ways slaves are treated. He remarks,
"I had resided but a short time in Baltimore before I observed a marked difference, in the treatment of slaves, from that which I had witnessed in the country. He is much better fed and clothed, and enjoys privileges altogether unknown to the slave on the plantation. There is a vestige of decency, a sense of shame, that does much to curb and check those outbreaks of atrocious cruelty so commonly enacted upon the plantation."
The slave owners in the North seemed to treat their slaves better out of shame for the treatment of slaves on plantations, which are differences that do not go unnoticed by Frederick Douglass.
As Douglass returns to life on the plantation, he yet again is surrounded by menacing slave owners who punish slaves with cruelty. He recalls, "Mr. Hopkins was even worse than Mr. Weeden. His chief boast was his ability to manage slaves. The peculiar feature of his government was that of whipping slaves in advance of deserving it." These slave owners and their treatments, as well as Douglass' experience in the North created in him a desire to escape before it was too late.  
As Frederick Douglass recalls much of his life in his autobiography, he includes details about slave owners and their treatment of slaves. As his story progresses, the reader is able to see the variety of owners, slaves, and treatments that can be found throughout the United States during the 1800's.