Final answer:
The economic transition in the United States during the first half of the nineteenth century was the Industrial Revolution, characterized by the move from an agrarian economy to an industrial one, marked by the use of new machinery and changes in production and labor.
Step-by-step explanation:
The United States underwent a significant economic transition in the first half of the nineteenth century, shifting from an agrarian society to an industrial economy. This change is known as the Industrial Revolution, and it involved the widespread use of power-driven machinery, transformations in national economies, international trade, social structures, and everyday life. The revolution, which began in Great Britain, quickly spread to the United States as a direct result of technological innovations such as the steam engine, power loom, and steam locomotive, leading to mass production and changes in the labor force.
The era's distinctive features included the discovery and usage of new raw materials, creation of ingenious inventions, and expansion of big businesses. These elements combined to dramatically alter the American economy and fundamentally change the lives of its citizens. The market revolution, as it was also known, signaled the departure from home production to factory production, where market forces like supply, demand, and price began to govern economic transactions rather than social relations, and individuals' reputations were based on their ability to honor contracts.