9. b. jim crow law
10. c. Granted each Indian family a 160 acre farmstead
11. d. Promontory, Utah
The main reason was because of over population in a small confined area. They also moved father out west so they could get more materials or supplies.
Answer:
A. Airplane
Explanation:
Around 1918, Air delivery, became the new mode of transportation for mail, as it rendered railroad services unnecessary. During this period, the Post Office moved on the airplane bandwagon early, there by, offering air mail service in the early 1900s.
Hence, the 1900's technological invention which allowed the U.S. postal service to deliver the mail considerably faster than previous methods is AIRPLANE.
