John Deere invented the steel plow in 1837 when the Middle-West was being settled.
IMPROVED ANSWER: John Deere's invention of the steel plow opened up the rich prairies of Indiana, Illinois, and Iowa.
John Deere
1837
John Deere was working in a saw mill, when the saw broke. He asked if he could keep the broken saw. He found out that the secret to a steel plow is the many thin layers that made up that saw.