What was ansel adams style of photography and reason for subject matter. what were they inspired by?

Ansel Adam was a nature photographer who lived in the United States. He shot mostly black and white images of landscapes and traveled to most of the National Parks in America capturing what he loved. He was really one of he first people to make photography an art form. Today his images are seen everywhere but are most often on calendars and book covers. He would wait for long hours to get the shot just right and did stunning long exposure shots. His camera was not small either, he'd hall a huge camera and tripod into the woods. He lived at one of the National Parks shooting images and was very close with president Roosevelt. He changed the way we see photography now and really made it an art form. 

Begin with the first image and just follow them in order.