What are some interesting facts about Shel Silverstein?

Shel Silverstein was an illustrator, songwriter, author and poet. He was most notable for his successful children's books and his illustrations.

• Shel Silverstein first established himself as a musician. He wrote a song called "A Boy Named Sue," which was made popular by Johnny Cash. Another of his songs, "One's On the Way," was sung by Loretta Lynn.
• He enlisted in the U.S. Army in 1950 and served in Korea and Japan. During his time in the Army, he worked as a cartoonist for "Stars and Stripes" magazine. After his time in the military, he began creating cartoons for other popular magazines, eventually gaining national attention with his cartoons he designed for "Playboy" magazine.
• He recorded a musical album in 1959 titled "Hairy Jazz." He later produced more than 12 addition albums throughout his career.
• He published his first children's book in 1963, "Uncle Shelby's Story of Lafcadio: The Lion Who Shot Back." He wrote his most popular children's book, "The Giving Tree," the following year.
• "The Giving Tree," which tells the story of a young boy and a selfless tree, was originally rejected by publishers because they felt the theme was too mature for children but too young for adults.
• Although Silverstein withdrew from writing and releasing books throughout the 1980s, he made a comeback with his 1996 release of "Falling Up."
• Shel Silverstein died of a heart attack in 1999 at the age of 68.