The major challenges to historical research revolve around the problems of sources, knowledge, explanation, objectivity, choice of subject, and the peculiar problems of contemporary history. Sources The problem of sources is a serious challenge to the historian in the task of reconstructing the past.
Answer: By working together voluntarily
Explanation:
Before the current time-zones in the United States and Canada came into effect, the various towns and cities had their own times depending on the position of the sun amongst other things. This made scheduling a nightmare for the Railroad comapnies who would have to list multiple times for the same train.
Burdened by this and powerful enough to change it, the Railroad companies met and decided to work together voluntarily to divide the United States and Canada into 4 zones which were quite similar to the ones in use today. These zones went into effect in 1883 and were officially adopted by Congress in 1918.
Not quite enough to answer really
Well differences are that now a data we don't get out to death or beaten for brakeing the law!