Today marks 116 years since the birth of famous American children's author Dr Seuss.

Theodor Seuss Geisel wrote more than 60 books under the pen name Dr Seuss, selling more than 600 million copies worldwide in more than 20 languages.

His birthday, March 2, 1904, is the annual date for National Read Across America Day, a nationwide initiative to promote reading.

On This Day: Popular children’s author Dr Seuss was born_1
Michelle Obama reads Green Eggs and Ham by Dr Seuss to children in 2010. Photo: Getty

Mr Geisel's work includes childhood classics such as The Cat in the Hat (1957), Greens Eggs and Ham (1960) and How the Grinch Stole Christmas (1957).

His quirky stories, told through rhyming couplets and accompanied by his colourful illustrations, were famously popular among children.

On This Day: Popular children’s author Dr Seuss was born_2
Mr Geisel working on a drawing of a grinch in 1957 for his book How the Grinch Stole Christmas. Photo: Getty

From encouraging readers to try new foods in Green Eggs and Ham, to promoting diversity and inclusion with How the Grinch Stole Christmas, Mr Geisel's books were a positive force for good during the political turmoil of the 20th century.

During World War II, Mr Geisel took a break from writing children's stories to illustrate political cartoons and produce animation films for the United States Army.

On This Day: Popular children’s author Dr Seuss was born_3
'A swift kick in the axis' drawn by Dr Seuss for the US Treasury Department's War Tax Program. Photo: Getty

A Democrat and supporter of President Franklin D Roosevelt, Mr Geisel  urged action against the Nazi's far-right political ideology before and after the US entered the war.

Once the war was over, he returned to writing and published some of his best-known books, such as If I Ran the Zoo (1950) and Horton Hears a Who! (1955).

Horton Hears a Who! is understood to be an allegory for the American post-war occupation of Japan.

The story promotes a lesson of equality and includes the quote: "A person's a person, no matter how small".

On This Day: Popular children’s author Dr Seuss was born_4
Mr Geisel wrote some of his most popular books after WWII, including The Cat in the Hat. Photo: Getty

Mr Geisel's last book, Oh, the Places You'll Go, was published in 1990.

Many of his witty quotes became so popular they are still used widely today.

Quotes such as, "Don't cry because it's over. Smile because it happened", are known to feature at graduation ceremonies and funerals.

Other favourites include: "The more that you read, the more things you will know. The more that you learn, the more places you'll go."

Dr Seuss died in 1991 at the age of 87.

On This Day: Popular children’s author Dr Seuss was born_5
Mr Geisel greeting readers in New York in 1986. Photo: Getty