A well-respected and prolific stage actor throughout the 1990s, John Slattery broke into screen acting at the end of the 1980s, and endured several failed series and guest spots in television movies and the occasional feature film. Recurring roles in a string of high-profile programs like “Will and Grace” (NBC, 1998-2006), “Sex and the City” (HBO, 1998-2004), “Ed” (NBC, 2000-04) and “Desperate Housewives” (ABC, 2004- ) made him a casting agent’s go-to for flinty and occasionally unyielding authority figures. Appearances in major motion pictures like “Traffic” (2000), “Flags of Our Fathers”