How much natural gas, coal, etc does it take to generate enough electricity for every electric car in America?

That depends mainly on how quickly America converts away from generating energy using gas and coal.

See for example the article: How much more energy will the US need to electrify everything?

Thank you @Zaku.

Also worth noting is that even if EVs are powered 100% by the dirtiest coal electricity, due to the efficiencies involved, it still puts out significantly less CO2 than a gas vehicle for the same milage. Of course as the grid gets greener, so do the EVs charging on it.

Thanks Gorilla guy. That’s what I was hoping for.