Lilly Ledbetter, whose lawsuit against her employer paved the way for the Fair Pay Act of 2009 and who dedicated decades of her life to fighting for equal pay, died on Saturday in Alabama. She was 86.

The cause was respiratory failure, a statement by her family said. It did not specify where in Alabama she died.

In 1979, Ms. Ledbetter got a job at the Goodyear Tire and Rubber Company in Gadsden, Ala. “We needed that money to pay college tuition and the mortgage,” she said at a Forbes Magazine women’s summit in 2021.

At first, Ms. Ledbetter earned the same as her male counterparts, she said. But over time, unbeknown to her, her pay had dropped “way out of line” compared with that of her male peers. At the factory, she said in 2021, employees could lose their jobs for sharing information about their salaries. It was not until 1998 that Ms. Ledbetter found out, by receiving an anonymous note, that she in fact earned much less than men working the same position.