Final answer:
Iron plows were not used to steer ships; instead, they were crucial in agriculture, while steam power revolutionized ship navigation.
Step-by-step explanation:
The statement that iron plows were used to steer ships is false. Iron plows were a significant advancement in agriculture, enabling more efficient farming, especially on the challenging terrain of the Midwest, as seen with improvements like James Oliver's chilled plow. In contrast, ships and their navigation were revolutionized by the introduction of steam power, as with Robert Fulton's steamship engine, which propelled vessels independently of the wind. They helped farmers break up the soil more efficiently, allowing them to grow more crops and feed more people. The introduction of iron plows transformed farming and led to the abandonment of the nomadic lifestyle.