Yes, though it is hard. Also, preexisting conditions vary, as far as definition, from one company to another. While it is easier to get coverage through an employer, you are able to get it via a private company.
chords to, I've come too far to look back
They can look as far back as they want to. Though most will only look for 5 years.
The question is somewhat unclear - BUT - it can look back as far as necessary to settle or answer the legal question being asked.
Three years.
Look far enough back, all dogs have.
Some states have rules about the length of the employers "look-back" but in reality, the information is out there as a public record, and they can research your adult record for as far back as they wish.
No, they look back three MONTHS on a hair test but they can look back as far as your hair will let them.
If you take a photograph from far enough above the earth, it looks like a map. Satellite photographs look like maps, for example.
It may depend entirely on the state in which you reside as to how far back the employment check may look, and for what purpose. In any case, without a court order no one (except the government) can look back at a juvenile record. In the case of government-authorized background checks - they may look as far back as they wish, even into your juvenile record and expunged offenses.
Artifacts can date back thousands to millions of years, depending on the material and preservation conditions. The oldest known artifacts, such as stone tools and cave paintings, date back to millions of years ago.
As far north as possible... polar regions preferably. It depends on solar conditions. In 2008 conditions are not favourable. Have a look at http://en.wikipedia.org/wiki/Aurora_(astronomy)