Did the telegraph do the most to spread the trend of nationalistic music especially in America?

The telegraph played a significant role in the dissemination of information, including music, but it was not the primary factor in spreading nationalistic music in America. The rise of nationalistic music was more directly influenced by cultural movements, the growth of the American identity, and the emergence of regional folk traditions. Additionally, the advent of radio and recording technologies had a more profound impact on the popularization of nationalistic music. While the telegraph facilitated communication and exchange of ideas, it was not the main driver of this musical trend.