Steve Irwin, the late Australian wildlife expert, conservationist, and host of Animal Planet’s The Crocodile Hunter TV show, will headline the 100th release in Grosset & Dunlap’s Who Was…? series of biographies. Irwin, who died in 2006 after being pierced by a stingray barb while filming an underwater documentary, was the winner of a poll the publisher conducted online and via ballot boxes in stores, schools, and libraries between March 1 and June 1 to determine the book’s subject. Of 67,000 respondents, 14,000 cast their votes for Irwin, and Who Was Steve Irwin? by Dina Anastasio will be published in May 2015.

Irwin joins a far-reaching roster of luminaries spotlighted by the series since its 2002 inception, among them Albert Einstein, Abraham Lincoln, Walt Disney, Anne Frank, Leonardo da Vinci, and Dr. Seuss. He was also in good company given the competition’s other top contenders, who included religious icon Mother Teresa, country music group Florida Georgia Line, “King of Pop” Michael Jackson, and Kenyan political and environmental activist Wangari Maathai.

Grosset & Dunlap v-p and editor-at-large Jane O’Connor is the editorial impetus behind Who Was…? A self-described “obsessive reader of biographies” as a child, she recognized more than a decade ago the need for books in that genre for early middle graders. “The Childhood of Famous Americans series got me reading biographies in second grade,” she said. “My sons are both big nonfiction readers, and I realized that there were likely a lot of other kids out there who also love nonfiction, and there.”

The editor’s hunch was spot on. Who Was…? has grown exponentially since its launch, registering an 800% leap in sales from 2002 to 2013. The series, combined with its spinoffs, What Was…? and the Spanish-language Quien fue…?), has sold more than 12 million copies and continues to flourish, with more than one million copies sold to date this year. Thirty new Who Was…? titles are scheduled for release in 2014, including biographies of Muhammad Ali, Queen Victoria, Clara Barton, Marie Curie, Henry Ford, Roberto Clemente, Julius Caesar, and Mahatma Gandhi.

O’Connor noted that the introduction of the Common Core curriculum, with its focus on nonfiction, has helped boost sales of the series “enormously,” and that there has been a marked uptick in trade sales in recent years. “We know that a lot of kids are going into stores to buy these biographies for book reports,” she said. “The series’ trade reach is now very wide.” In a Who Was…? back-to-school promotion planned at Barnes & Noble stores, customers who buy two of the series’ titles will receive a free pack of trivia playing cards (that can also be purchased separately).

Expanding from Who and What to Where

A new companion series to Who Was…? and What Was…? debuts in February 2015, when Grosset & Dunlap releases the first four titles in Where Is…? The seeds of this offshoot line were planted by Nico Medina, senior managing editor of Grosset & Dunlap/Price Stern Sloan, whom O’Connor affectionately labeled a “geography geek.” She recalled Medina’s comment that as a child “he could not read enough about different places,” which, she added, “got me thinking about a series focusing not so much on geography as landmarks. In elementary school, I hated books about things like a location’s average annual rainfall and altitude, but was excited by landmarks – whether natural or manmade.”

The series’ launch list encompasses both. Due out are Where Is the Grand Canyon? by Jim O’Connor, illustrated by Daniel Colón; Where Is the Great Wall? by Patricia Brennan Demuth, illustrated by Jerry Hoare; Where Is the White House? by Megan Stine, illustrated by David Groff; and Where Is Mount Rushmore? by True Kelley, illustrated by John Hinderliter. Two books will be added to the series each season, for a total of six new volumes annually.

Future Where Is…? titles include those focusing on the Twin Towers, to commemorate the 15th anniversary of 9/11; and on Mount Everest, which Medina (author of several YA novels and Who Was…? biographies) is writing. “Nico included some geography facts in Where Is Mount Everest?, but tucked them into a really exciting story,” said O’Connor. “I learned some fascinating things, including the fact that there is a species of spider that can survive way up near the summit of Everest, because it lives on dead flies that snow blows upwards. I just loved that! It’s been really fun editing these books.”