Blount's Inventions were not purchased by any company in the United States because their inventions were not unique.

A E. Brown has written:

'Absolutely mad inventions' -- subject(s): Miscellanea, United States, Inventions, United States. Patent Office, Patents, History

Inventions have helped all nations. Which inventions and what help they have provided depends on the nation and the invention was. You need to be more specific.

Many were invented in the United States by Americans.

The military tank was one of many inventions in 1914.