Answer:
The answer is <u>steamship</u>
Explanation:
Robert Fulton is an engineer and inventor. He is best known for developing the first successful commercial steamboat, <u>the North River Steamboat</u> which carried passengers between New York City and Albany, New York.
As a successful engineer, he was commissioned to designed an under water boat by Napolean in 1800 leading to the founding of the first successful submarine known as the <u>Nautilus</u>
A slave is a person that belongs to another one and is treated as property. Serfs, I'm not so sure about this now, were renting the land out from the landowners.
The civil war improved the economy of the north, but harmed the economy of the south. The south relied heavily on agriculture/ producing cotton on slave worked plantations. The civil war led the slaves to finally be freed thus sending many southern farmers into poverty.