"Uncle Tom’s Cabin" refers to the small home that Tom, a main character, creates with his wife Chloe on his master’s property in Kentucky, before his master sells him south. The small house a place of domestic comfort even to Tom’s master’s son, who spends many hours at the cabin reading the Bible out loud to Tom. The cabin represents not only domesticity, but also a sort of freedom even while in servitude. After being sold south, Tom loses his wife, children, and the freedom of movement that his first master had given him.
However, the subtitle, "Life among the Lowly," is just as important. According to an afterword by literary scholar Alfred Kazin, which appeared in the Reader’s Digest 1991 edition of the book, the subtitle demonstrates Stowe’s intent to show that slavery is not just an individual sin but a systemic cruelty "based on profit, whatever the human cost." While Stowe was probably not a socialist, there are several conversations in Uncle Tom’s Cabin that indicate slavery is the natural result of capitalism and hierarchical class structures. (Note that Uncle Tom’s Cabin has had several different subtitles, but Life Among the Lowly is the most common.)