The most obvious American composers would be the classic ragtime composers, most notably Scott Joplin and James Scott. Joplin in particular was influenced not only by African-American folk music but also earlier Romantic classical composers, including Chopin, whose music he played as a piano student. Ragtime, in turn, had a direct influence on a selection of early 20th century classical composers, and then had a more indirect influence through jazz, which influenced even more 20th century classical composers. Elsewhere in the New World, I would nominate the Brazilian composer Ernesto Nazareth, who specialized in writing Brazilian tangos for solo piano. Joplin, James Scott, and Nazareth are sometimes programmed together because they were contemporaries a each other—the classical pianist and Bach scholar Joshua Rifkin made an excellent recording of these three composers' music compiled on a single album. More on reddit.com

Brahms More on reddit.com

There isn't one. Beethoven is often cited as the person who made the stylistic change, but he wasn't writing in a bubble - Weber was writing stuff sounding a lot more like the direction of Schubert while Beethoven was writing his decidedly classical 7 & 8th symphonies. The romantic era itself had so much stylistic change in it that trying to ascribe a start and end point to it is impossible. Wagner was writing the Ring Cycle and was paving the way forward for late romantic harmony while Mendelssohn was still writing like Schubert. It's a general term used to describe the change in music during the 19th century, not a specific school of composition. More on reddit.com

He is definitionally a romantic composer. There is no debate More on reddit.com