Joss Whedon on Getting the Idea for Firefly

Joss Whedon, Future History: the Story of the Earth that Was (Serenity bonus material)

On season 2 of Buffy, I get my two week vacation and the second book I read is The Killer Angels which is about the Battle of Gettysburg and right after that I sort of become obsessed with life on the frontier and this, of course, makes me think of the Millennium Falcon because most things do.