Letterman returned to "The Late Show" to bid farewell to the show he originated in 1993 before handing over the reins to Colbert in 2015.

From the start of his career as a late-night television star on CBS, Stephen Colbert shattered the long-established broadcast network mold for who and what makes a late-night host.

Before their rooftop adventure, Letterman took to the couch to chat with his successor – he arrived to a standing ovation from the audience and the house band’s rendition of the White Stripes’ “Seven ...