The answer would be D, stage choches were developed last.
Answer:
Differences between the slave states and the non slave states, Bleeding Kansas, and secession,
Washington served as a general and commander-in-chief of the colonial armies during the American Revolution, and later became the first president of the United States, serving from 1789 to 1797
i think its either c or a but im not entirely sure but i hope this helps you a little more then nothing.