A young Irish Catholic immigrant who came west to find fortune with his brother Mickey, Sean became estranged from his brother after Sean's unrequited infatuation with Protestant minister Ruth Cole drove a wedge between them. After finding work as Cullen's railroad accountant, Sean found his loyalties divided once again after Durant recruits him to work as his spy in Hell on Wheels. After getting mixed up in a murder investigation, Sean was shot and killed by Mickey.
Ben Esler was born and raised in Melbourne, Australia. While obtaining his masters degree in philosophy from the University of Melbourne, he got his start in acting appearing in guest roles and commercials on Australian television. Esler made his international debut in 2010 in the Tom Hanks and Steven Spielberg executive produced HBO miniseries The Pacific. His other television credits include the award-winning World War II era television movie Curtin for ABC Australia and recurring roles on the Seven Network's Blue Heelers.