Final answer:
The period from 1865 to 1889 saw the United States undergo dramatic changes, with large numbers of immigrants fueling urban and industrial growth, leading to the transformation of American society from a rural to an urban one. The government played a key role in these changes by supporting railroads and setting the stage for economic growth post-Civil War. Technological advancements such as electric lights allowed factories to locate in urban areas and operate around the clock, increasing the need for a local workforce and contributing to the rise in urban populations.
Step-by-step explanation:
The period of reconstruction, urbanization, and industrialization from 1865 to 1889 was marked by significant transformations in American society. The rapid increase in America's industrial output following the Civil War was partly spurred by the labor of a substantial number of immigrants arriving annually. These immigrants mostly worked in urban environments, which despite not being their ultimate goal, became critical stations in their journey toward potential prosperity. The notion of returning to their homelands was widespread, which led many to forgo the efforts of fully assimilating or learning the English language.
With industrialization taking a stronghold, the population and economic size of the United States rose substantially, contributing to the growth of urban areas in the East and Midwest. Government involvement played an essential role in this growth by providing land grants and other concessions to the railroads, which themselves were catalysts for increased federal centralization and subsequently led to a more extensive regulatory framework in the early twentieth century.
The tremendous increase in the population of major cities like New York City, Chicago, and Philadelphia from the end of the Civil War to the start of World War I underscores the magnetic pull of urban centers, owing to changing industrial dynamics. Technological advancements such as electric lights and steam-powered machinery allowed factories to be built near population centers, and operate continuously, thereby necessitating a workforce to reside in close proximity. The cities, hence, became hubs for the new wave of immigrants and nascent industrial laborers. This convergence of immigration, urbanization, and industrialization reshaped American society from a primarily rural one toward a significantly urban one.
Concerning policies that contributed to post-Civil War economic growth, several wartime measures, such as the Homestead Act and the granting of land to railroads, provided the infrastructural and policy frameworks that encouraged westward expansion and economic development, which were fundamental to the industrial upsurge.