An American children's and educational author, poet, and philanthropist, he is known for his works in both English and Spanish. His children's books include At the Farm, The Book Monkeys, and All About Snakes.
He served in the U.S. Coast Guard before attending Richard Stockton College of New Jersey.
He donated 400,000 books to American schools in 2009.
He was born in West Chester, Pennsylvania. His father was an Irish immigrant to the United States.
He and fellow Pennsylvania native, Marc Brown, are both known for their works of children's literature.