Plantation owners turned to the enslaved Africans as a labor force because they were not paying them for their work, instead they were just providing shelter and food for them. Also, they had total control over them because they owned them, thus were able to make them work as much as they wanted and the slaves couldn't do anything about it.
The correct answer is option D. "Companies replaced hand-operated brakes with air brakes on trains". The development of air brakes on trains was a significant improvement of railroad safety. Air brakes function much more faster than hand-operated brakes, because hand-operated brakes required that the brakemen turned the brakes in one car and jump to the next to set the brakes on, and so on.
Answer:
In 1862, the Central Pacific and the Union Pacific Railroad Companies began railroad that would link the United States from east to west.
Explanation:
All state governments are modeled after the federal government and
consist of three branches: executive, legislative, and judicial. The
U.S. Constitution mandates that all states uphold a "republican form" of
government, although the three-branch structure is not required.
Mining and farming towns developedest describes the early use of Oklahoma lands by Europeans
