If “Downton Abbey” is sort of PBS’ Super Bowl, then the network hopes “Mercy Street” becomes the after-show.

The public-broadcasting outlet has ambitious plans for “Mercy,” the first U.S. drama production it has mounted in a decade. The Civil War drama follows the lives of two nurses, played by Mary Elizabeth Winstead and Hannah James, on opposite ends of the massive conflict. In an attempt to generate the biggest possible audience, PBS will launch the new show off of what ought to be a guaranteed large lead-in: the sixth and final season of “Downton Abbey.”

“Mercy Street” is “the thing you want to bring as many eyeballs as possible to, and we get such an incredible audience for ‘Downtown,’” said Beth Hoppe, PBS’ chief programming executive and general manager of general audience programming, in an interview. “It’s an opportunity to connect the audience.” PBS will launch “Mercy Street” after the third episode of “Downton Abbey” airs on January 17.

The fifth season of “Downton Abbey” was viewed by 25.5 million people, according to PBS. The season won a weekly average audience of 12.9 million viewers over a nine-week span, compared with a weekly audience of 13.3 million in its fourth season. The series has been one of the biggest hits on PBS in years. As such, the broadcaster will try drawing attention to it with a float in the Tournament of Roses Parade in early 2016.

PBS has generally avoided U.S. productions for drama series, but Hoppe said the broadcaster had secured philanthropic gifts and an international distribution deal that made “Mercy Street” viable.

The two series will air as part of a season that also includes a new Ken Burns documentary about baseball hero Jackie Robinson; a 90-minute episode of “Sherlock”; a tribute to Willie Nelson; and a series of “American Masters” devoted to Carole King, Janis Joplin and Loretta Lynn.