TORONTO — “Welcome to the running of the anti-feminists,” said Coco Francini, an executive producer of FX’s new limited series “Mrs. America.” Behind her, in the parking lot of an amusement park outside Toronto, dozens of background actors dressed tidily in pea coats and pumps milled about holding handmade signs blaring, “Lesbians go home” and “Read the Bible while you’re able!”

The camera rolled and Cate Blanchett — sporting a pair of pearl earrings and a voluminous blonde updo covered by a prim white bonnet — switched on a high-wattage grin as she looked upon the fruit of her labor. Tucked into the crook of one arm was a clipboard with a red octagonal sticker on the back: In white block letters, it read, “STOP E.R.A.”

“Mrs. America,” which debuts April 15 on FX on Hulu, stars Blanchett, also an executive producer, as the right-wing activist and political organizer Phyllis Schlafly, who led the charge to successfully defeat the Equal Rights Amendment in the 1970s. The series, created by the former “Mad Men” writer Dahvi Waller, unearths an illuminating and somewhat forgotten historical episode — a political battle over a woman’s place that helped permanently alter the course of both American conservatism and the feminist movement.

The result is a sprawling, ambitious series that spans a decade and features one of the most impressive ensemble TV casts of 2020. For Blanchett, Schlafly was a role — her first in an American TV series — that challenged easy categorization. Schlafly, who died just before the 2016 election, spent much of her life fiercely advocating traditional women’s roles, yet that work took her out of her own home. She preached the dangers of feminism to the American way of life, yet she was also a kind of feminist in her own right.