Final answer:
Scott Joplin is recognized as the best-known composer of ragtime music, chiefly due to his influential composition 'Maple Leaf Rag' which helped popularize the genre in the United States.
Step-by-step explanation:
The best-known composer of ragtime music is Scott Joplin. Scott Joplin was an African American composer and a pivotal figure in the development of ragtime music. He was born in Texas and moved around the South, eventually settling in Missouri. He also spent time in Northern cities like Chicago. Joplin's compositions helped popularize ragtime on a national level, with pieces like "Maple Leaf Rag" becoming widely known and contributing to the ragtime craze. His music was distributed via sheet music sales, which allowed ragtime to flourish as a uniquely American music genre. Despite the contributions from other musicians of the era, such as blues singers and jazz pioneers, it was Scott Joplin who emerged as the quintessential ragtime composer.