Lincoln honored the soldiers who fight in the battle of Gettysburg. He also wanted to remind Americans of their sacrifice for America and for them
An objective that's common to both capitalism and socialism (and thus mixed economies) is production. Both systems rely on the production of goods and services (except that in capitalism one produces for profit and in socialism one produces for use--i.e. one produces according to human needs, not wants).
It increased the demand for steel since steel was used to make railcars and tracks.
Steel was used to make railroad tracks and cars because it was the only metal strong enough. So the expansion of the railroad industry would mean more steel had to be used and thus it would increase the demand.
