The play "Harvey" premiered on Broadway in 1944. Audiences went gaga. It features a man named Elwood Dowd whose best friend is a large rabbit. The catch is: no one but Elwood can see the rabbit. Harvey became a feature film-- starring Jimmy Stewart. Playwright Mary Chase won a Pulitzer Prize for Harvey. She was a life-long Denverite who grew up in a working-class Irish family. There's a new biography of Chase, who died in 1981. It's called "Pulling Harvey Out of Her Hat." Author Mimi Pockross spoke with CPR's Andrea Dukakis.