When Constance Wu landed the part of Jessica Huang, the Chinese-American matriarch on the ABC sitcom “Fresh Off the Boat,” she didn’t realize just how significant the role would turn out to be. As she developed her part, Ms. Wu heard the same dismal fact repeated over and over again: It had been 20 years since a show featuring a predominantly Asian-American cast had aired on television. ABC’s previous offering, the 1994 Margaret Cho vehicle “All-American Girl,” was canceled after one season.

“I wasn’t really conscious of it until I booked the role,” Ms. Wu said. “I was focused on the task at hand, which was paying my rent.”

The show, which was just renewed for a third season, has granted Ms. Wu a steady job and a new perspective. “It changed me,” Ms. Wu said. After doing a lot of research, she shifted her focus “from self-interest to Asian-American interests.”