Before “This Is Us,” Milo Ventimiglia had only a cursory familiarity with Pittsburgh. The Southern California native had been here a few times doing branded-content work with American Eagle Outfitters at its South Side headquarters, but he had never thought too critically about what it means to be a yinzer.

That changed when he got the role of Jack Pearson on “This Is Us,” the wildly popular NBC drama that will begin its sixth and final season Tuesday at 9 p.m. Ventimiglia and Mandy Moore, who plays Jack’s wife Rebecca, were tasked with anchoring a Pittsburgh-set storyline that would serve as the formative years for their children Kevin (played in the future by Justin Hartley), Randall (Sterling K. Brown) and Kate (Chrissy Metz).