The "Ferguson System" used a three-point implement-mounting arrangement with hydraulic lift and draft control that would eventually become an industry standard. Ferguson's three-point mounting setup used two solid lower links that did the pulling/carrying and a single top compression link with a control spring that exerted a downward force on the tractor. The action of the upper compression link helped to keep traction on the tractor's rear wheels and, by compressing and releasing the control spring, the link activated the hydraulic system, providing automatic depth control. Also, if the implement encountered an immovable obstacle such as a root or a rock, all hydraulic pressure was relieved and the tractor's rear wheels would begin to spin. This was a huge step forward in terms of operator safety, as it prevented the tractor's front wheels from lifting off the ground unexpectedly, potentially turning the machine over.
The tractor's overall dimensions should permit 14 of them to be loaded in a railroad box car for efficient shipping, Ford advised his engineers, and parts had to be drawn from existing Ford vehicles--this would keep production costs low and make servicing the tractors easy and inexpensive.
http://forums.aaca.org/topic/207364-vintage-delivery-trucks-on-main-street-usa-a-pictorial/?page=32
https://www.hemmings.com/magazine/hmn/2013/04/1939--49-Ford-Ferguson-9N/3724431.html