"as a question of property rights" is the best option as to how slave labor in America was primarily seen in the 1850s, since it was an issue of state's rights.
I think it’s A. 907-960 CE
Answer:1800–1842. 1821: Spain cedes Florida to United States (Adams–Onís Treaty).
Answer:
Hitler broke the treaty of Versailles in 1938 by putting troops in the demilitarized zone between France and Germany. He also invaded Poland and annexed Austria despite the warnings not to by the later to become Allied Powers.
Explanation: