Answer:
a. growing cities in the East
b.new railroads and refrigerated cars.
c.barbed-wire fences
Step-by-step explanation:
The 1800s were a period of discovering economic potentials in the United States that saw many ventures being initiated. Coupled with new technologies, theses ventures such as meat production and mining, saw profits increase and became big businesses.
Cattle for example experienced a massive growth that was brought by the cities in the east growing in size and demanding more meat to feed their populations. This demand coupled with new railroads and refrigerated cars meant that the meat could be transported long distances to these cities without worrying about them getting spoiled.
Also, with improvements in barbed-wire technology, land-owning ranchers could prevent other livestock from grazing on their fields while they themselves allowed theirs to graze. This led to cows eating healthier and therefore having more meat.