"In 1788, when Andrew Jackson, then a young man of twenty-one years who had been living in the Carolinas, still a virgin country, came into Tennessee, a turbulent place of unknown opportunities, to enforce the law as the new prosecuting attorney, he had the necessary qualifications for the task."
This appalling paragraph, which I've brazenly stolen from the The Harbrace College Handbook, is a perfect example of how run-on sentences and excessive detail can destroy a reader's will to live.
At the risk of destroying my own readers' will to live, let's deconstruct this awful sentence in order to forever avoid writing in this way:
a young man of twenty-one years is both redundant and irrelevant.
who had been living in the Carolinas contains a compound verb--a no-no in good writing. Use who lived instead.
still a virgin country leaves me scratching my head. Why is this bizarre phrase even included? What does it mean? Most importantly, who cares?
The phrase a turbulent place of unknown opportunities ought to be in a photograph next to the dictionary entry for purple prose. Delete it.
to enforce the law as the new prosecuting attorney is also redundant, although fortunately not entirely irrelevant. As the new prosecuting attorney is sufficient.
he had the necessary qualifications for the task should be replaced with he was qualified.
Let's look at the book's corrected version, which is better but still terrible:
In 1788, when Andrew Jackson came into Tennessee as the new prosecuting attorney, he had the necessary qualifications for the task.
Yes, this version is vastly improved. It's tighter, it uses the rule of three with some modest effect, and it contains less irrelevant and redundant information. I didn't lose my will to live after reading it. However, it's still boring, and it contains pointlessly trivial information.
Which leads me to the most important insight of all: please have mercy on your readers, and don't subject them to bland and boring writing that provides no value.