Can someone answer the following question:  On this date in history,
what was the most shocking news event that ever took place (e.g. On
this date their was a slave revolt in mississippi in 1845)

Dear Dose, 

You can find what happened, historically, on each day, through Wikipedia. 

For example: 

Wuikipedia, October 16th
<http://en.wikipedia.org/wiki/October_16> ; 

If you need something more news-oriented, the BBC also runs its "On the Day" site: 
On This Day - October 16
<http://news.bbc.co.uk/onthisday/hi/dates/stories/october/16/> 

The "importance" of an event depends upon our cultural and historical
perspective. One might say that the execution of Marie Antoinette is
the most shocking (1793), another - focused on Chinese history - could
claim that the begin the Long March is of great important and "shock"
- "it ended a year and four days later, by which time Mao Zedong had
regained his title as party chairman." (1934) is more important; or
that the establishment of the Warshaw Ghetto (1940) is a shocking,
decisive event.

The fact that Karol J&#243;zef Wojty&#322;a became the pope (1978) is
certainly not "shocking" (though it might have been a surprise, given
the fact that he was from Poland), but is important and in fact, is
the chosen headline by the BBC.

I hope this answers your question. Please contact me if you need any
further clarification on this answer before you rate it.

Take your choice:

http://www.historychannel.com/tdih/tdih.jsp?category=leadstory