Read the passage. Chief among these [economic developments] was the rise of a great cotton-growing industry in the South, stimulated by the introduction of new types of cotton and by Eli Whitney’s invention in 1793 of the cotton gin, which separated the seeds from cotton. At the same time, the Industrial Revolution, which made textile manufacturing a large-scale operation, vastly increased the demand for raw cotton. And the opening of new lands in the West after 1812 greatly extended the area available for cotton cultivation. Cotton culture moved rapidly from the Tidewater states on the East Coast through much of the lower South to the delta region of the Mississippi and eventually to Texas.

–"Westward Expansion and Regional Differences,” Outline of US History,
US Department of State

While innovations in cotton production impacted the economies of the Southern states, which innovation of the Industrial Revolution in the early 1800s most positively impacted the economies of Northern states?

The introduction of the incandescent light bulb enabled manufacturing operations outside of daylight hours and an overall increase in production.
The expansion of canals linking major rivers and the Great Lakes enabled rapid and cost-effective transportation of raw materials and finished products.
The implementation of time zones by the growing railroad industry enabled more efficient transportation of goods and communication.
The advancements in steel production enabled the construction of high-rise buildings, offering greater floor space for manufacturing at a lower cost.