On this day in 1889, Thomas Edison showed the 1st motion picture using Kinetoscope he had invented. Some people may argue that this was one of the most important inventions in history. What do you think was the most important invention ever and why?

On this day in 1889, Thomas Edison showed the 1st motion picture using Kinetoscope he had invented. Some people may argue that this was one of the most important inventions in history. What do you think was the most important invention ever and why? 

The nail is one of the most important inventions in all of history. Without nails our civilization would definitely crumble. None of our important structures would stand or withhold without them.