Pick up trucks were first designed and put into production in the mid 1920s, around 1925 specifically. The design for those first few pick up trucks looked how you would imagine vehicles in the 20s would look like. Old-fashion cab with a fiberglass-wood hybrid build for the box. Fast-forward 25 years to the 50s where motor companies like Chevrolet, GMC, and specific to this blog post, ford, redesigned how trucks were built and functioned.
The first year of production for the Ford model F100 was in 1948, and was made until 1983 with slight tweaks to the design here and there. An example of an adjustment Ford made was to the windshield of the truck, first released in their 1956 model. The windshield shift can be seen in the 1st and 3rd images where the Blue truck (1954) has a flat windshield, and the third picture (1956) has a windshield that wraps around the cab of the vehicle.
The middle picture is included because of the popularity of the Ford tailgate from these F100 models. They are, in-fact, very rare and difficult to find for a restoration project and trucks from this era are often without a tailgate because of the rarity of them. The reason for this is because these tailgates can be used as stand alone display pieces or other vintage projects like making the tailgate the backrest of a bench or something similar.