A cargo loading system for use with a truck bed including a first frame, a second frame connected to the first frame by a first hinge, and a third frame connected to the second frame by a second hinge. Each frame includes perimeter walls and a bottom wall that define a cargo space. The first frame includes wheels extending beyond the perimeter walls on a side of the cargo space opposite to the bottom wall. In a first configuration, the frames lie in parallel in the truck bed. In a second configuration, the third frame and the second frame lie in parallel in the truck bed, and the first frame freely hangs over an edge of the truck bed. In a third configuration, the third frame lies in the truck bed, the second frame hangs freely, and the one or more wheels engage a surface below the truck bed.