Evolution of Transportation 147 • During the stone age of antiquity, we walked and ran upon the solid earth and swam and floated in dugout canoes upon the liquid rivers or seas. • By 3500 BC, we began using wheeled carts and river boats. By 3100 BC, we tamed horses to assist our way. • By 2000 BC, we built chariots. By 600 BC, we built wagons. • By 332 BC, we built submersibles. • By 312 BC, we built miles of paved roads. • By 236 BC, we constructed our first elevators. • By 214 BC, we built canals. • By 200 BC, we constructed manned kites to fly.