Religion
Though it is not at the forefront of Northup's narrative, religion plays a crucial role in his story. Northup uses religion to emphasize which characters are "good" and which are "bad." For example, Tibeats and Epp both swear profusely and use God's name in vain, emphasizing their poor character. By contrast, Ford never takes God's name in vain and is depicted as a devout worshiper of God. Ford even holds sermons and invites his slaves to participate in sharing the word of God. In 1853, when this book was published, these characteristics would have stood out to readers. Furthermore, Northup portrays himself as a religious person on multiple occasions, such as when, after successfully fleeing through a snake-infested forest, Northup credits God for his survival. Religion was comforting to slaves held in bondage, offering them visions of an afterlife in which they could be free from suffering and connect with those they'd lost on earth.
Sexual Assault
Misogyny (and the resulting sexual abuse) is a vital piece of Northup's commentary on slavery. In his initial introduction of Patsey, Northup describes how, as "The enslaved victim of lust and hate, Patsey had no comfort of her life" (135). As a female slave, Patsey was forced to succumb to Epp's sexual violence and physical violence. She not only belonged to him as a means of picking cotton, but for sexual gratification as well. This inspires the jealousy that leads to the violence Patsey experiences near the end of the novel, wherein Epps whips her until she is unconscious. A male slave would not have been subjected to this, and Northup recognizes this in his narrative: "If ever there was a broken heart — one crushed and blighted by the rude grasp of suffering and misfortune — it was Patsey's" (188). Slave women were thus subject to all of the arduous labor, capricious punishments, and emotional trauma of slaves in general, but they also faced the added tortures of rape, abuse, and pregnancy with a master's child.
Identity
Identity drives Northup's narrative. At the beginning of the narrative, prior to his enslavement, Northup's identity is one of an affluent, well-liked, and talented violinist. Not only that, but his identity is also one of a free man. Following his enslavement, however, his identity is stripped away: he is no longer "Solomon"; instead, he is "Platt." His identity is now that of a slave: when he insists that he is free, he is beaten until he stops insisting. He is no longer allowed to move through the world however he likes, instead being forced to yield to what white people expect of him. His identity — at least outwardly — is forced to completely change. Internally, however, Northup remembers his past identity, which inspires him to survive. He finds value in the violin; he never gives up trying to escape; he is faithful to his wife; he always remembers who he is and what he wants to return to.
"Man's Inhumanity to Man"
Northup reveals just how awful man can be to man. The lucrativeness of slavery and concomitant racism created a situation that the South jealously guarded. In order to keep it intact, many felt that black people must be stripped of all rights and must be frightened or manipulated into working hard and knowing their artificially subordinate place in society. Violence and abuse of all kinds began to come naturally to slaveowners, for deep down they were aware of the flimsiness of their claims that slavery was a positive force. Fear of rebellion also stoked their increasingly cruel treatment of slaves, and when violence went on for so long unchecked, it became the norm. Man's baser impulses — such as greed, selfishness, and desire for power — cannot easily be ignored or quelled in the context of slavery.
Slavery's Corrupting Influence
Not only was slavery problematic for the African Americans caught in its grasp, but, Northup writes, it also corrupted any and all in its path — including white people. It made white people who were otherwise kind or moral into tyrants. It raised children in an environment where brutal treatment of slaves was considered the norm. Violence, sexual abuse, and cruelty were de rigeuer on many plantations; owning slaves and doing what one wanted with them was seen as right and normal. Even the generous and Christian Mr. Ford was raised in this milieu. Mrs. Epps was otherwise a wonderful woman, but she was corrupted by having power over Patsey, the slave with whom her husband had relations. Overall, slavery was bad for the economy and environment of the South, bad for free labor, bad for slaves, and bad for the white people who participated in it.
The Dignity and Humanity of Slaves
Northup does not depict slaves as mindless cogs in the machine of plantation slavery: rather, they are alive and unique. They may vary in terms of their intellect and personality, but they understand their conditions, desire freedom, and seek to make their lives as meaningful as possible even when their autonomy is limited in all respects. They form relationships, make a little money on the side, rebel and/or try to escape, play music, dance, share stories, and ultimately reveal their humanity. This allows his work to resonate with readers in that they can recognize the "characters" as authentic human beings.
Abolitionism
The text makes it seem as though Northup knew it would become a core part of the abolitionist movement in the North. He doesn't hit readers over the head with this, but his descriptions of the terrible things slaves endure, the corrupting influence of the system on white people, the problems for free labor, the hypocrisies of the system in light of the nation's founding principles, and the normalization of family disintegration seem to be calculated to shock and move readers to action. Northup is entirely forthright and thorough; he does not lie or omit or embellish. His work needed to be solid so it could be touted by abolitionists as a visceral example of why slavery must be abolished. Almost every page echoes with Northup's firm belief that slavery was immoral and untenable.