An interlocking ladder system for transporting at least two ladders which are stacked together. The ladder system includes a first ladder having a first end cap having a cap portion and an engagement portion with a slot, a second ladder having a second end cap having a cap portion and an engagement portion with a slot, and preferably a third end cap having a cap portion and an engagement portion with a slot. The slot of the engagement portion of the second end cap engages with the slot of the engagement portion of the first end cap when the second ladder is stacked on top of the first ladder. The ladder system may include a third ladder having a fourth end cap having a cap portion and an engagement portion and a slot. The slot of the engagement portion of the third end cap engages with the slot of the engagement portion of the fourth end cap when the third ladder is stacked on top of the second ladder. The second ladder stacked on top of the first ladder and preferably the third ladder stacked on top of the second ladder all together form a stack. A method for stacking ladders into a stack.