N. C. Wyeth was an American artist and illustrator. Born in Victorian times, he created his most famous works, including the illustrations to Treasure Island in the early 20th century, had overall a very successful career creating about 3000 paintings and illustrating 112 books, became a father of 5 children who inherited his artistic talents, but unfortunately, was killed in a car crash at the age of about 63 together with one of his grandsons.
Brought up on a farm he spent much time outdoors engaging in such pursuits as hunting and fishing and his sense of observation helped him later in his works. N.C. Wyeth had a keen interest in Native American culture, spent some time working as a cowboy, painted farm scenes and illustrated books about European history, such as Robin Hood or The White Company.
Below are some of his paintings courtesy of WikiArt:
Lancelot and Guenevere:
A Native American:
The cover of Treasure Island:
You can read more about N.C. Wyeth on Wikipedia.
Here is the link to his works on WikiArt.