Rules were laid down in this century by people who wanted to run everyone else's life, not their own. The most influential was Bishop Robert Lowth who wrote "A Short Introduction to English Grammar" where many rules were laid down for English using Latin as the template. English evolved from Teutonic languages and was simplified and clarified by in its grammar and syntax by the Vikings. No Latin grammar was ever part of the language until these self - appointed arbitrers tried to force it to be so.

Bishop Robert Lowth
Awesome Grammer Site
Less Awesome but much knowledge
Conventional Grammar Explaination and clear too

Mercantilism evolved from Capitalism
Mercantilism generated the American Revolution.
Physiocrats French Mercantilism
Mercantilism Academic discussion

The Theory Originator's Version
Simplier Version