Ford's F-100 truck remained in the lineup for 1975, but got a stablemate. The F-150 was introduced that year as a "heavy duty" half ton pickup.
Ford's SuperCab body, with its fold-up seat, was introduced the same year. The original SuperCabs had just the two front doors, so getting in and out of the back seat was a little more difficult than accessing the second row in today's trucks.