RE: #2 with the rocklock!
Yep, John Deere in 1837...He left his family (and bills) and went to Iowa where he took a steel saw blade, made a plow and polished thesteel so the black, sticky soil wouldn't stick (like it did on cast iron) and the rest is history...
The oldest is DuPont in 1836...Named after a Frenchman who came over here and started making black powder...