(cause and effect) why did spartans enphasize military training? ?

Spartan society operated on a system of mass enslavement. The peoples of Messenia were enslaved as helots, and worked Spartan land so the citizens spartiates could , in accordance with the rules of the mythical Lycurgus , be fulltime professional soldiers. As this went on, a series of revolts made the Spartans relise that to keep the helots pacified , Sparta would need to continue its tradition of training all young men to the point of military excellence

Transcontinental railroad was the most effective way to travel.