How a high schooler’s obsession became a biography

David Wilson for the Boston Globe

“I’ve always been really interested in the musicals of the 1930s and ’40s,” said Holly Van Leuven. Even as a high school student, Van Leuven searched online for videos of her favorite performers. One in particular fascinated her: Ray Bolger, who beyond his star turn as the Scarecrow in “The Wizard of Oz’’ had a long career in vaudeville, Broadway, television, and film.

“A few months prior to going to college, I noticed there were about 25 new Ray Bolger videos that had hit YouTube,” Van Leuven said. She sent a message to the user who had uploaded the videos, asking where they were from. Months later, now a student at Emerson College, living in a dorm room above the Colonial Theatre, Van Leuven got a response from a woman named Sylvia Lewis.

“She said, ‘I was Ray Bolger’s dance partner. I am the woman in these videos,’ ” Van Leuven said. “She was astounded that somebody who was 18 or 19 years old was interested in these films and these shows. I was amazed that she had these stories to tell, and she was very generous in sharing them.”

Ten years later, after being the first researcher to access the treasure trove of Bolger’s archives at UCLA, Van Leuven has published “Ray Bolger: More Than a Scarecrow,” the first biography of the legendary dancer and actor.

Bolger’s roots in working-class Boston shaped him, both as a dancer and a man (“that Boston accent is so present; he never tried to hide it,” Van Leuven said), but his career took him to New York, Los Angeles, and Oz — at the height of his fame, he was the opening headliner at Las Vegas’s Sahara hotel. “He had a rich career that survived so many different iterations of media in the 20th century. I began to describe him as the Forrest Gump of American entertainment.”

Van Leuven will discuss the book at 5:30 p.m. March 21 at the Massachusetts Historical Society.