The correct answer is the ''Japanese''.
First, they wanted to stay out, then they started to help England and France, and finally when Japan attacked they totally got involved.
The latest projection is that French will be spoken by 750 million people by 2050. A study by investment bank Natixis even suggests that by that time, French could be the most-spoken language in the world, ahead of English and even Mandarin.
The answers are:
Meriwether Lewis, William Clark and Sacagawea