What is the origin of the phrase, "Two o'clock and all is well"? Why was the time called out in this way and what determined if things were well or not?

It goes back (at least) as far as the Civil War where the prison camp guards (North and South), were required to call out (throughout the night) their post and the hour:

"Thus," recalled one prisoner, "at ten o'clock the cry would begin 'Post number one — ten o'clock and all's well.' 'Post number two — ten o'clock and all's ...


http://books.google.com/books?id=mXPQ8S5_m0QC&pg=RA1-PA267&lpg=RA1-PA267&dq=would+cry+o'clock+and+all+is+well&source=web&ots=aadXTETajE&sig=UMNhFkjoW1QPYruWpUVLcYfbk0I&hl=en&sa=X&oi=book_result&resnum=6&ct=result

No, I think cartoonist Johnny Hart invented it in 1964 when he created "The Wizard of Id."

In medieval towns, night watchmen guarded against invasion, thieves, and particularly fire. Town criers called people to early mass and made announcements.

I'm having a hard time finding good online references, but this is the origen--some say it went back to Greek and Roman times, but they wouldn't have said "Two o'clock"--and the meaning was there was no trouble or danger.

http://www.britainexpress.com/History/Townlife.htm