Final answer:
During the Civil War, there was a dramatic increase in the number of cattle in the western frontier, particularly in Texas. Ranchers took advantage of the completion of the first transcontinental railroad to transport the wild steers to eastern markets. This led to the rise of big business ranching and a boom in the cattle industry.
Step-by-step explanation:
During the Civil War, there was a dramatic increase in the number of cattle in the western frontier, particularly in Texas. Before the war, there were around five million longhorn steers in Texas, but few settlers were able to claim them due to the difficulty of transporting them to eastern markets. However, with the completion of the first transcontinental railroad, cattle ranchers took advantage of the opportunity to round up the wild steers and transport them by rail to be sold in the East. This led to a rampant speculation in the cattle industry and the rise of big business ranching.