Why were diseases the greatest threat to the existence of american indians?

Because the diseases were unknown to them, they spread easily and could kill off thousands of their kind.

answer: d. joseph james clark​

explanation:

while it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton.

explanation:

before eli whitney's invention of the cotton gin, picking and cleaning cotton was a slow, labor-intensive job. workers, usually slaves, had to pick the seeds from the cotton fibers by hand. this invention made it possible to grow large amounts of cotton on big farms and make money.