Eli whitney’s invention of the cotton gin and new farmlands in the west (westward expansion) led to

the right answer is the third one: turnpikes went short distances to connect markets. turnpikes, also known as toll roads, were very important for trade and transportation (of people, goods and products) in the 19th century, coinciding with the expansion towards the west. they contributed significantly to the economic development of the united states.

the answer i chose to believe is 'harmony'