The US purchased the Florida Territory from Spain... i think that was in 1819
Technically he could be considered to be a freedman, because Illinois outlawed slavery. However, the Supreme Court ruled that his time spent in Illinois didn't change the fact that he remained a slave after his master died, so he was not empancipated, and thus was still a slave.
The answer is D: He was a slave.
I'm pretty sure it was the Spanish conquering South America, and exploiting its resources. Hope this helps.