why was the south in favor of the mexican american war ?
LuLu or Jessica or Moise or Dona or Sally or Kilo or J or Ray or whoever,
Posting in multiple names is silly. In addition you should learn to use a search engine. You could find many of these answers yourself.
I went to http://www.google.com and entered mexican american war and this is among the search results:
http://en.wikipedia.org/wiki/Mexican-American_War
Be sure to read the second paragraph carefully.