Because the allied powers were a team that were not about to break apart and the axis powers would have kept attacking them if only on of the allied powers made peace.
Colonists had many reasons for leaving Europe and coming to the New World. Some only had a small area of farming land in Europe and expected to get bigger farms in America. Others were fed up with wars and rebellions that went on in Europe and made it unstable. They wanted peace and a quiet life. Another group thought it was easy to make money and get rich quickly in America. Farmers in the south saw a chance to earn a lot by growing and selling tobacco.
But most people came for religious reasons. Many European kings and queens forced their people to have the same religion that they had. Most settlers came to America because they wanted religious freedom.
(hope this helped
