I came across this expression from a book on Americanisms. Here's what it said:
About East.—To the frontiersman or pioneer, the Eastern or New England States are typical of all that he cherishes most and loves best. The vicissitudes of his rough Western life, the toil and hardships he has undergone while battling with nature and building up a new habitation far from the old homestead, all predispose him to turn with longing eyes and undying, though quaintly exaggerated love, to the East—the home of his fathers. A famous Yankee character (Major Jack Downing) makes use of the expression that he would "Go East of sunrise anyday to see sich a place." Everybody and everything connected with the East, i.e., his native land, is commendable. To his mind they cannot be surpassed —hence the things he would hold up to admiration he says are about East, i.e., "about right." Indeed, it is surprising what a strong hold this idea has upon the minds of men. Many a familiar phrase recalls the old times and the old folks to memory, which, in this respect, is evergreen. They talk of Going Down East, that is, to New England, while the DownEaster is neither more nor less than the pure and veritable Yankee.
Source: Americanisms ©1889
Unfortunately this was the only reference I found regarding this term. I found it in other books but always referring to a direction, not the term being quoted above.