The great depression during the 30's was happening and so was the dust bowl in Oklahoma<span />
<span>The correct answer is that their processes were lengthy unlike many other colonies where a swift revolution ended it all. For example, Belize fought for its independence for over 20 years, and it ended with the UN asking for independence. Macau had 4 talks over 10 years regarding its transfer of sovereignty from the Portuguese government and it ended successfully. </span>
I can tell you who invented them: Benjamin Franklin. And, while he wasn't president, he is on the $100 bill. It did happen during the time period Declaration of Independence, which he signed.