When were these boxing organisations created??

When were weght classes divided and why? i.e junior etc...

Thanks.

These organizations were all created because somebody saw a business opportunity.

Check out this link, should answer all of your questions
http://www.boxrec.com/media/index.php/Weight_divisions

Er.. off the top of my head..

WBA is the original don
WBC around '68 or 9
IBF around '82 or 3
WBO around '89

The rest of em? No i-dee-ya!

Oh yeah, Sugar Ray Leonard created the supermiddleweight division with his bare hands

Boxing must've been bad ass in the early 1700's with just Heavyweight and Other lol.

Holmes made the IBF legitimate and the WBC was essentially created as a result of ali's absence (As you'll note its inaugural match was in 1970 between frazier and ellis). Atleast thats what it looks like. I'm not sure how the wbo became big time.