Many of the military leaders on both sides of fought as junior officers decades earlier in the mexican war, including ulysses s. grant, stonewall jackson, jefferson davis, and robert e. lee.

I believe the answer is the civil war.those are all military leaders that fought in the civil war. I can't remember what side Jackson and Davis were on, but Grant was for the Union, while Lee was for the Confederacy

The transcontinental railroad provided a means of fast transportation. it cut a 6 month trip into 6 days, created jobs for many people and encouraged immigration. the homestead act played a huge role in western expansion; it allowed settlers to begin a fresh start, and gave them land in exchange for their residence for up to five years and a small fee.