Howard Pyle was a very talented American artist and illustrator (1853-1911). He also started an entire school of painting and illustration - his students, including N.C. Wyeth (one of my favorites), Maxfield Parrish (remember HIM?), Jessie Willcox Smith (too cutesy for my taste), Harvey Dunn (a GREAT painter), and Frank Schoonover (don't like his work much) were collectively known as the "Brandywine School" - he lived in Wilmington DE but taught summer classes at Chadds Ford PA.
He not only did pirates - he also did King Arthur, Robin Hood (I have a copy - it's great, he adapted the text and it's all illustrated with woodcuts), Pepper and Salt and The Wonder Clock, collections of stories for children, a story of the German wars called Otto of the Silver Hand, historical paintings and murals, and hundreds of magazine illustrations.
Samples follow.