How did the development of barbed wire in the 1870s change the cattle ranching industry?

Barbed wire was an invention that completely transformed the American West. Before the invention of barbed wire, cattle was generally allowed to roam freely, as settlements and farms were few and far in between. This free roaming was also convenient when the cattle needed to travel long distances to be sold in the East.

However, after the invention of barbed wire, the protection of range rights became easier to enforce. Large areas of land were enclosed much more easily. Moreover, livestock was a lot less likely to cross range boundaries.The invention was durable, cheap and effective, which made it very common in the West.

This reduced the availability of grazing land for cattle, with many dying when they could not find a way around the fences. Cattle was now contained to smaller parcels, which also meant that the cattle needed less supervision, reducing the need for cowboys, and leading to the decline of this tradition.

d. the polar jet stream   lies between the polar easterlies and trade winds should be your answer