Why did european nations form alliances in the late 1800s and early 1900s\?

How did the union blockade of the southern coast affect the confederacy? it forced the confederacy to build new railroads. it contributed to shortages of weapons and food. it encouraged europe to trade with the south. it halted all trade, leaving the south without supplies.

Describe how the ways in which african americans migrated during the great migration were similar to the immigrants who arrived from other countries in the early 1900s.

The immigration act of 1924 was considered outdated by the 1960s