I never thought about it before, but before the El Camino, Hudson had a car/truck. I don't think anyone gives them credit for that, simply because they went out of business so long ago

I think these are both 1947s

and then I was reminded... 

that the 1937 Studebaker Express was nearly 20 years earlier. Factory built car front with a truck box backend 

https://blog.hemmings.com/index.php/2010/12/30/hemmings-find-of-the-day-1937-studebaker-coupe-express/