the phrase everything old is new again makes me wonder how many times great inventions had to be invented before they gained traction. Everyone knows that iPod

the phrase everything old is new again makes me wonder how many times great inventions had to be invented before they gained traction. Everyone knows that iPod wasn't the first portable HDD music player, but will people know that in 200 years? What inventions from 200 years ago do we attribute to the wrong people? (tesla/edison is one obvious example, but I'm sure there are some that no one knows about.)