Because there was no other way or method to get their cattle to market. Trucks never existed back then, railroads were too slow to be built on time to get their cattle from their ranch all the way to the market, and the cattle trails provided an easy way to find their way from the ranch to the market place.
Ranchers hired cowboys to gather and drive the cattle east. The expansion of the railroads shortened the cattle drive, enabling the cowboys to simply drive the cattle to the nearest rail stockyard.
yes
Because there was a much larger population back East than there was out West.
Texas Ranchers sent their longhorns on cattle drives because the demand of the cattle in Texas was low. But high in the north and east. Demand and supply affect the price of nearly everything that was bought and sold - not just the cattle.
Because that's where most of America's population was, and more food was needed there than in the South and West of the USA.
Before the arrival of the railways, cattle were driven to market, known as a cattle drive. When the railways arrived, the cattle were driven to the nearest railhead.
They herded them using horses and the best herding practices they could use to move cattle with and keep them together.
Cattle ranchers sent their cattle to the north and east because those regions provided better grazing land and access to major markets and transportation routes for cattle distribution. Additionally, these regions often had lower population densities and less competition for resources compared to other areas.
Joseph McCoy had promised the Texan ranchers that if they brought their cattle to Kansas, where they could be shipped by rail, that he would pay them well for the cattle. The ranchers received three times what they could locally for their cattle, which greatly increased the profitability of ranching.
A lot of cattle ranches were in vast open spaces away from big cities like New York. There was a limited transport network so the easiest way to get livestock from A to B was to walk them. They were taken to railheads in places like Kansas for shipments to stockyards in Chicago and farther east. This also insured fresh beef or pork where it was required, i.e the cities.
Texas ranchers grouped their cattle into herds and marched them across the countryside to get to the railroad to be shipped east or west. This was called a cattle drive and needed about 4 or more people on horseback to control where the cattle went.
The longhorns were the only cattle available in America to be used for beef and to send East for beef and for a bit of income.