Although history-based stories were once considered too stodgy for TV audiences, the period drama is all over broadcast, cable and streaming services these days. Just five years ago, the 1960s-set AMC series Mad Men was the only series among the five Emmy drama nominees that wasn’t set in the modern era. Compare that to last year, when three out of the six were period pieces (and one other, True Detective, jumped back and forth in time).

History’s creative comeback doesn’t surprise Masters of Sex showrunner Michelle Ashford, whose third season of the 1960s-set series about pioneering sex researchers debuts on Showtime July 12.

“Historical stories have always been some of the greatest yarns you’ll ever hear, and they’re appealing because you get to dive into a world that is not ours,” Ashford explains.

Cinemax’s The Knick, FX’s The Americans and AMC’s Halt and Catch Fire and Better Call Saul are just a few of the shows taking a closer look at the 20th century, while others like AMC’s Turn, History’s Vikings and Netflix’s Marco Polo and Peaky Blinders reach even further in time back for their storylines.

Mad Men gets a lot of the credit for ushering in this era of reflection on TV, which is something that’s relatively new for American shows, says Downton Abbey producer Gareth Neame.

“America has not been a country that’s as comfortable and quite possibly as obsessed with its past as the British are,” Neame explains. “Why it’s changed is that storytellers have started to comment on the 20th century. With Mad Men, looking at this extraordinary 15 to 20 years in modern American history allowed audiences to think it’s OK to look back. And if there are great stories happening today there are hundreds, thousands of years of history behind us that also had great stories we can mine.”

Advances in technology have helped remove the boundaries of achieving whatever storytellers can dream up. When Boardwalk Empire’s Terence Winter started writing the pilot for the HBO series, he thought re-creating the bustle of 1920s Atlantic City would be almost impossible.

“You can’t do a show called Boardwalk Empire without actually showing the boardwalk,” says Winter, who changed his mind about the possibilities after seeing a behind-the-scenes featurette on the visual effects used in HBO’s 2008 Emmy-winning John Adams. “Technologically, we have the ability to re-create these worlds, and I don’t know that we did 15, 20 years ago. You can do anything you can imagine. It’s really incredible.”

Neame also points out that historical dramas tend to be more commercially viable in territories outside of the U.S.

“A big piece like (NBC’s limited series) A.D. The Bible Continues will travel extremely well around the planet, whereas a lot of contemporary American shows can be big hits domestically but nobody’s looking at them to do tremendous business globally,” Neame says.

The research that goes into a historical drama can be more intensive than a contemporary piece, but the real challenge is in finding actors who look the part, particularly when plastic surgery is so much a part of modern culture.

“We have a book of mugshots from the 19th century, and people just look different,” Winter says, pointing to the rise of plastic surgery. “You get (modern) people (who) just look too healthy. When we get (actors) who come in with a scar or a cauliflower ear, even if the guy can’t act, we keep his picture on file because he has such a great period look.”

Historical shows are really just another way to examine modern life through a different lens, Ashford says.

“When you look at TV shows that have tackled a period of time, they have this added layer of depth because it’s somehow speaking to something urgent and current while at the same time immersing you in a world that takes you out of yourself,” she concludes. “When you can put those two together, the material just feels richer.”