Final answer:
Ragtime widely used the 'March form', with Scott Joplin being its most famous composer, and compositions like 'Maple Leaf Rag' were pivotal in the genre's spread which also influenced the development of jazz.
Step-by-step explanation:
The genre that widely used "March form" is ragtime.
Ragtime is a uniquely American form of music that incorporated "ragged" rhythms and a strong beat, often causing listeners to tap their feet or dance. The most famous ragtime composer, Scott Joplin, contributed significantly to this genre through compositions such as "Maple Leaf Rag", which spread the popularity of ragtime music.
John Phillip Sousa, another musician from this era, used the tempo of ragtime to create popular band music, specializing in stirring marches for military bands.
Therefore, ragtime and its march form were essential to the cultural landscape of American music in the early 20th century, bridging the gap between African American musical traditions and broader American musical tastes, eventually leading to the birth of jazz.