The Late 19th to Early 20th Century refers to a transformative period in American history characterized by rapid industrialization, urbanization, and significant economic shifts. During this time, the United States transitioned from an agrarian economy to an industrial powerhouse, marked by innovations in technology, changes in labor practices, and the rise of corporate entities. This era also saw the expansion of the working class, as well as social movements aimed at addressing the inequalities and challenges posed by this new economic landscape.