Thus she has lain Black through the years. (7-8)
OK, so this is really the polar opposite of transformation. Angelou creates an image of stasis so we can see just how devastating the transformations of Stanza 2 actually are. Notice the sense of eternal continuity in these lines. It makes it almost impossible to imagine that anything would ever change. Of course, that's why the changes seem so unbelievable to begin with.
Thus she has lain. (17)
Tricked you! You thought we were done with this quote, didn't you? Well, here's the sneaky part – it actually appears several times in the poem. At the end of Stanza 2, however, it means something drastically different than it did in Stanza 1. Now it's a poignant testimony to all that the continent has suffered at the hands of slavers. The land may lie without change, but its people are being uprooted.
Now she is rising (18)
Any time you read the word "now" in this poem, chances are it's a transition away from a "then" – a past that's now over. It's a sure sign of change, folks – and this time, it's change for the better.