Bravo Sierra.
Mr. Case is charged with providing for his HOGS, not himself, as evidenced by the statement that it was 'a great trouble to feed them'. He plants potatoes for the HOGS, who will root the potatoes themselves, 'saving not only the labor of feeding the hogs, but also that of digging the potatoes'.
Nowhere does he allude to Mr. Case planting potatoes for himself. Lincoln was alluding to the former slaves, not to Southen planters.
When if comes to bovine excrement then who better than you should know?
President Lincoln was responding to Mr. Hunter, a member of the so-called 'peace commission'. Mr. Hunter wasn't concerned with the freed slaves. It is obvious by his concern about the ruin of southern society. His fear that work would not get done, crops wouldn't be cultivated. His fear was the loss of his chattel, the workforce that did the cultivating in the first place. Those were the hogs that had to root or die, the hogs that had to face a future where they did the work, they did the cultivating, they didn't have their slaves to fall back on. President Lincoln was addressing Mr. Hunter's concerns when he made his statement, so his remarks were obviously addressed to the white hogs, not any black ones.