American music really started in New Orleans. Congo Square was the seed of just about all original American music.

I had the great fortune to play in New Orleans a few times with Jim Lampos. I always loved the vibe & spirit of the people of New Orleans.
Some great musicians from New Orleans:
Louis Armstrong:
Professor Longhair:
The Meters:
Fats Domino:
Branford Marsalis:
I know there are a ton of great musicians from New Orleans, but these 5 came to my mind instantly:
Louis Armstrong-The King of American Music. He is the root from where we all grow.
Professor Longhair-King of News Orleans Piano
The Meters-Cissy Strut changed my concept of rhythm when I was younger.
Fats Domino-Always loved his music and he was a prominent face of Katrina survivors.
Branford Marsalis-The concert that changed my life was in 1986. I saw Sting on his Dream of the Blue Turtles Tour. I was a sax player at the time. I saw Branford Marsalis and I thought he was the coolest musician I'd ever seen. The next day I went out and bought Scenes in the City & Royal Garden Blues. It was in the liner notes where I read that he attended Berklee College of Music. He is the reason I attended Berklee and continue to pursue music as a career.