Final answer:
The United States economy changed from being dominated by agriculture to being dominated by industry during the period from 1870 to the early 20th century, due to the Industrial Revolution, technological advancements, and the rise of big business and factory jobs.
Step-by-step explanation:
The economy of the United States experienced a significant transformation during the period from 1870 to the early 20th century. Initially, the U.S economy was largely agricultural, with most Americans involved in farming. However, with the Industrial Revolution, there was a pivotal shift to an industrialized economy. This change was propelled by a series of factors, including the discovery and exploitation of raw materials, groundbreaking new inventions, the expansion of big businesses, and advances in transportation and technology.
During the Industrial Age, America's economy moved from being dominated by agriculture to being dominated by industry and manufacturing. The creation of the factory system, improved transportation like railroads, and technological advancements in both agriculture and industry all played a part in this shift. The industrialization led to mass production, and the American workforce increasingly moved from the farms to the cities to take up industrial and factory jobs.
The period was also marked by the market revolution, where Americans transitioned from home-based production to factory-based production, creating a robust domestic market less reliant on imports. While the primary sector of the economy, which includes agriculture, continued to be important, technological advances in mechanization allowed for increased agricultural output with fewer laborers. As a result, industrial production became the dominant force in the U.S. economy.