The Ford F-Series made its introduction on January 16th of 1948, beginning the legacy of F-Series trucks. Since that time, over 32 million trucks have been given the F-Series badge. These trucks have been the best-selling pickups for 36 consecutive years, and America's overall best-selling vehicle for over three decades. The fourth generation of the F-Series began in 1961 and continued through 1966. The fourth generation had a unibody construction, integrating the cab and the box. Unibody construction means there are no gaps between the bed and the cab, and is set atop a traditional frame-style chassis.