Just use boats. This is also true today.
“when it comes to moving large volumes, the sea changes everything. The fundamental problem with transporting food on land is that the energy to transport the food must come from food, either processed into muscle power by porters or animals. But at sea, that energy can come from the wind. So while the crew of a ship eats the food, the ship can be scaled up without scaling up the food requirements of the crew or the crew itself.”