because people that was a dum azz said so

The important role of Culture, Commerce, Trade, and Industry. Hope this helps :)

It solidified the idea that America had fulfilled it's "Manifest Destiny" in the mid 1800s and began the development of American Imperialism.

Voice communication through the Internet is the most advanced and latest technology nowadays. This technology was created in the mid of 90s which has increased the value and importance of Internet communication.

dynamite declined in importance from about one billion pounds in the mid-1950s to approximately 100 million pounds in 1993.