Final answer:
George Washington Carver developed multiple uses for peanuts, sweet potatoes, and soybeans, contributing to agricultural extension and improving the livelihoods of southern farmers in the early 20th century.
Step-by-step explanation:
George Washington Carver, an influential American scientist and inventor, is best known for his work on agricultural extension in the southern United States during the early 20th century.
While the provided texts refer to various historical crops and agricultural practices, Carver's most notable contributions were related to the development of multiple uses for peanuts, sweet potatoes, and soybeans.
He discovered over 300 uses for peanuts ranging from cooking oil to printers' ink and more than 100 for sweet potatoes, including the creation of a synthetic rubber.
This work was not only significant for its immediate economic benefits but also for its role in promoting crop diversification and improving the livelihoods of many southern farmers.