| Quote #1
I sometimes wonder that we can be so frivolous, I may almost say, as to attend to the gross but somewhat foreign form of servitude called Negro Slavery, there are so many keen and subtle masters that enslave both north and south. It is hard to have a southern overseer; it is worse to have a northern one; but worst of all when you are the slave-driver of yourself. (Economy.9)
Thoreau was strongly anti-slavery. That "almost" ("I may almost say") suggests that he knows himself that he might be making a rather questionable claim here. For most people, being the "slave-driver of yourself" would have still been preferable to being a slave to somebody else, by whatever standard. Thoreau's just not most people, though.
| Quote #2
The man who has actually paid for his farm with labor on it is so rare that every neighbor can point to him. I doubt if there are three such men in Concord. (Economy.49)
Here, our author laments the fact that farming is no longer done for survival, but for profit. Farmers – including Thoreau's own neighbors and friends – are thus led into debt.
| Quote #3
It is a mistake to suppose that, in a country where the usual evidences of civilization exist, the condition of a very large body of the inhabitants may not be as degraded as that of savages. (Economy.52)
Thoreau criticizes the wide gap between the rich and the poor. Not everyone is enjoying the benefits of industrialization. The wealth gap is a huge issue even today, and something that a lot of brilliant men and women – like Thoreau – spend a lot of brainpower trying to resolve.