Final answer:
Increased agricultural productivity was a consequence of internal improvements in the North by the 1850s, due to advancements in canal, railroad, and steamboat transportation.
Step-by-step explanation:
By the 1850s, a consequence of internal improvements in the North was increased agricultural productivity. These improvements included the expansion of canals, railroads, and steamboat transportation which facilitated easier and cheaper shipping of agricultural products to markets and manufactured goods in the opposite direction. As a result, rural families experienced less isolation and the market revolution thrived, impacting social and economic structures.