Final answer:
The popularity of specialty magazines in the United States began in the 19th century, spurred by technological advancements and a developing American literary culture.
Step-by-step explanation:
The idea of specialty magazines focused on specific topics began to gain popularity in the 19th century in the United States. Notable examples from this era include the founding of National Geographic in 1888, which catered to audiences interested in science, geography, history, and world cultures. Technological advancements such as the invention of the telegraph and the linotype machine revolutionized the print media industry, making information dissemination faster and allowing for the publication of materials aimed at a variety of interests. Alongside general newspapers, special-interest magazines became increasingly common, reflecting a burgeoning American literary and publishing industry and fostering a flourishing literary culture. By the close of the 19th century, Americans were consuming a diverse range of printed materials, underscoring the establishment of specialty media as a significant facet of American culture.