How did manifest destiny affect US history?

Answer:
It was the encouragement of Americans to move westward and inhabit that land!
So yes, it did help America stretch from sea to shining sea! The annexation of Texas to the US, which caused the Mexican War, which of course, affected US History. TEX-MEX!
Contributor: Boomba
First answer by Scubaluver1. Last edit by Mr.Volcano5. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 0 [recommend question].