What was the root of the idea in having a united nations?

there had always been a spirit of peace in europe.
earlier organizations had attempted to stop wars.
the americans had introduced plans for an international group of nations after world war i.
during world war ii, the idea was being planned for this assembly.

the industrial revolution pushed the world into modern industrialization. it changed the course of history profoundly. it caused rapid urbanization and pushed cities and countries into development. the industrial revolution began in great britain with a series with new inventions which led to the creation of machines and mass production.

this caused the country to gain wealth and money and become an international superpower. it improved transportation and manufacturing inside the country, pushed people to live in urban areas and britain to become the most powerful nation in the world for a while.

missouri compromise of 1820 which prohibited slavery