War
War times make people very patriotic or nationalistic.
Cars enabled people to travel and relocate more readily
What ultimately brought the US out of its neutrality was when the Germans wanted to stop supplies from getting to Great Britain from the US. So, they sunk the supply ships which also had hundreds of Americans on board which the Germans killed altogether (triggering their anger and causing them to join the war).
They made sure that their pharohs were buried with specific things and jackles were surrounding the tomb to guard them in the afterlife
Because " taxation without representation." They didn't want to be taxed for every single thing they had to buy from Europe.