Top ten American composers/songwriters

Carla Bley please!

The "list" is almost entirely men.

Mildred J. Hill wrote the most popular song of all time. She should make every list yet no one knows who the is. I had to look her up!

Perhaps a split between composers/songwriters would be better?
Also different genres of music too? I could toss off many Jazz greats but not a single hip hopper, gospel, metal, or trance composers/songwriter. 

History of popular songs yes. History of composers and songwriters, a footnote.
Carol King has been suggested. Not sure why so few women composers/songwriters. Plenty of feminine involvement in classical performance. I don't think we feel threatened any longer. Would be a great thread to explore. 

The BEST one is Samuel Barber !

And coming from Schubert completely makes sense. It was between Barber and Copland. Copland more American imho.

Was Jim Morrison not mentioned?

Also, was the OP speaking of all genres or just rock/pop? If all, then maybe top 10 for each of the major genres: jazz, blues, pop, rock, classical...and each of these have distinctive sub groups.