Dean Winters and John Patrick Amedori were originally cast in the roles of John and Andrew Haplin in the first pilot. They were later replaced by Steven Weber and Ben Schnetzer.
When filming the "Thawfest" carnival scene for the series pilot, the cast sweltered in their winter coats with the actual temperature hovering above 60 degrees F. The scene location, Montebello Park in St. Catharines, Ontario, Canada on April 2, 2009, had been snow-free for almost 2 months.
Kim Poirier was originally cast in the role of Miranda Kirby for the show but was replaced by Linda Kash the night before shooting.