A cantilever assembly includes a cantilever arm having a pair of longitudinal fastening channels with a corresponding pair of slots in communication with the fastening channels. An attachment bracket features a connector portion and a pair of spaced leg portions defining a seat there between with each leg portion having at least one aperture. The leg portions also each have an inner surface featuring an elongated groove with each being in communication with a corresponding one of the apertures. The elongated grooves are positioned in alignment with the slots of the cantilever arm when the cantilever arm is positioned in the seat of the attachment bracket. Tee bolts having a shaft portion and an oblong head portion movably pass through the apertures of the attachment bracket with the oblong head portions pivotable between a first orientation where they may be positioned within the elongated grooves of the attachment bracket and passed through the slots and into and out of the fastening channels of the cantilever arm, and a second orientation where they are secured within the fastening channels of the cantilever arm.