Final answer:
The cattle industry expanded with the development of the transcontinental railroad but faced decline with innovations like barbed wire and the rise of large meatpacking plants.
Step-by-step explanation:
With the end of the Civil War, the cattle industry both grew and declined along with the development of railroads, barbed wire, and large-scale meatpacking industries. The completion of the transcontinental railroad enabled ranchers and businessmen to round up cattle and transport them to eastern markets profitably.
Simultaneously, new inventions like barbed wire enabled ranchers to fence off their lands, signaling the end of the free range era. Furthermore, the consolidation into big business was exemplified by the rise of large meatpacking facilities like those established by Philip Armour and Gustavus Swift, which shipped processed meat instead of live animals, marking the decline of local butchery and transforming the American diet.