Embodiments of a modular cargo system for use with a vehicle, such as a pickup truck, may include side rails and stanchions securing the side rails to the vehicle. At least one hoop may be provided for connection to either the stanchions or the side rails. Each hoop may include a plurality of legs, a clamp connected to each leg, an elbow connected to each leg opposite the clamp, and a lateral cross bar connected between the elbows. Bed dividers and storage lockers or boxes are disclosed for use with embodiments of a cargo system as applied to a pickup truck. Elevated rails may be attached to the hoops. A cargo loading device for moving cargo into and out of the vehicle is also provided. A cover may enclose a portion of the vehicle, such as the truck bed.