Although an early form of democracy was tried in ancient Greece, the idea of a republic came from the Romans.

new immigrants arriving after the American Revolution.

the German Renaissance.

ancient Egypt.

The effect of penicillin was an improvement of life in general. Basically many things that were killing people almost became eradicated because penicillin was effective and efficient and the life expectancy of people increased drastically. The effect of the atomic bomb was that people started building atomic weaponry and living in fear of mutually assured destruction so it cause a sort of peace based on fear of the other.