How did the U.S. utilize the idea of manifest destiny in the early to mid 1800s? give 2 examples?

(My Original Blog Post: http://www.latesttrendsguide.com/?p=1953)

I'll be more specific now. I needs to be about the Mexican-US war and the gadsden purchase. and i need these 2 to be explained out a little.
THANKS!

By: Nikki