African slaves in the United States adapted a number of European instruments, most notably the violin, to more traditional African music. European-Americans in turn popularized the music in minstrel shows.
One of the first major figures in the musical form was Louis Moreau Gottschalk. He adapted the African-American minstrel music into piano renditions. This became popular prior to the Civil War.
The rise of ragtime music popularized some of the African-American jazz performers themselves. In 1895, Ernest Hogan gained a major hit with "All Coons Look Alike To Me." Scott Joplin joined him in 1899 with his international hit "Maple Leaf Rag."
What ultimately became known as early jazz was developed in New Orleans. A number of African-American artists performed in brothels and bars using marching band instruments. They merged ragtime with funeral-procession music to create a new style.
The origin of the word "jazz" is unknown. According to the American Dialect Society, it appears to have been used as slang during the early part of the 1900s. It first appeared in print in the "San Francisco Bulletin" on March 3, 1913.