Theodor Seuss Geisel was born on March 2, 1904, in Springfield, MA. After graduating from Dartmouth College in 1925, he studied literature at Oxford University in England, but he left without a degree after deciding that he did not want to be a college professor. He returned to Springfield in 1927 to begin his new career as an artist and writer. After sending his work to numerous magazines, he made his first sale to The Saturday Evening Post, which published one of his cartoons in its July 16, 1927, issue. Shortly afterwards he moved to New York City and joined the staff of the humor magazine Judge, where he first used the pen name Dr. Seuss.

In 1936, after a successful stint in advertising, Geisel authored the first of his 44 books for children, And to Think That I Saw It on Mulberry Street. The rhyming text combined with illustrations was unusual in children's books at the time, and 27 publishers rejected the manuscript before Vanguard Press published it in 1937. Reviewers recognized that Dr. Seuss had created a new kind of book that appealed to a child's imagination and sense of humor.

Subsequent books by Dr. Seuss introduced characters who became part of American popular culture, such as Horton the elephant in Horton Hatches the Egg (1940) and Horton Hears a Who! (1954) and the Grinch in How the Grinch Stole Christmas! (1957). Dr. Seuss books typically feature a story in verse seasoned with zany humor and illustrated with drawings of fantastic creatures. Although his books often teach a lesson about virtues like compassion and loyalty, they are never preachy.

Many consider The Cat in the Hat (1957) his most innovative book. Challenged by an editor to write a groundbreaking book for beginning readers that was imaginative and fun, Geisel worked from a vocabulary list of only 225 words. It was an immediate success and is now considered one of the most influential readers ever written. "Children want the same things we want," Geisel once said. "To laugh, to be challenged, to be entertained and delighted."

The last two books written and illustrated by Geisel reflected the wisdom of his years. You're Only Old Once! (1986), a wry look at aging for adult readers, was subtitled "A Book for Obsolete Children"; it was published on his 82nd birthday. His final book, the best-seller Oh, the Places You'll Go! (1990), offered encouragement to the young as they set out on the journey of life. He died on September 24, 1991, in La Jolla, CA.