What were some of the reasons african americans moved to the north during this period?

In the 1920s, more than 750,000 African Americans left the South--a greater movement of people than had occurred in the Irish potato famine of the 1840s. The large-scale relocation to the Northeast and West brought many other changes with it, as many largely rural people moved into cities for the first time.

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain

d. dr. francis collins