A commercially built example
image copyright Cozy Cruiser Mfg Inc.
The Teardrop was first invented by 'bodgers' in the Great Depression to allow the masses to have access to cheaper vacations. They originated in workshops and barns across North America to the bodgers own designs and and also by following rough plans from magazines such as Popular Mechanics.
I just loved the idea and had to build one. You can read my build thread over on the excellent Teardrops & Tiny Travel Trailers Forum of which I am a member. In the meantime, here is the end result of my efforts...
Here are some more photos, including some of the build process.