Complex sentence: At the union of 1707 England had about five times the population of Scotland, and about 36 times as much wealth; however, Scotland began to experience the beginnings of economic expansion that would begin to allow it to close this gap.
Split into simpler sentences: At the union of 1707 England had about five times the population of Scotland, and about 36 times as much wealth. Scotland experienced the beginnings of economic expansion that allowed it to close this gap.