What factors led to the decline of the Whig party in the early 1850s

The Compromise of 1850 and the expansion of slavery led to the end of the Whig Party.

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.