I'm reading Lincoln to understand the occupation. This is going to be one of my ongoing themes, might as well tell you now, how Lincoln worked at himself over 3 decades to bring slavery down. No, the occupation isn't slavery, it is another species of evil, and we are as implicated in it as all the U.S. was in slavery in the 1800s. As a 21-year-old visiting New Orleans, Lincoln saw "a slave auction where a fine mulatto girl was being pinched and prodded and trotted up and down the room like a horse to show how she moved, that 'bidders might satisfy themselves'...of the soundness of the article to be sold... [His friend said,] 'Lincoln saw it; his heart bled; said nothing much, was silent. I can say, knowing it, that it was on this trip that he formed his opinion of slavery. It ran its iron into him then and there, May, 1831.'" (Abraham Lincoln, Lord Charnwood).
Thanks to Eva Smagacz for the link.