The US often provided funds and materials to help rebuild what was destroyed by the war, but the US also stayed in countries to help them rebuild - possibly restructure - the governments.
The US turned into a superpower
i have no idea.
The role of Mobile, Alabama was a significant role in the US Civil War. The city passed several resolutions even passed a resolution to succeed from the Union.
The Korean War.
To destroy the enemy.
yes
united states
they were an allie in 1914 before the US joined the war
You need to specify WHICH war, or at least when. There has been more than one.
It was the only role. Otherwise the US would have stayed out of it.
The US became a combatant, part of the allies in 1917.
around 1950