Liberty Tavern has a long, proud history in Powell. The pub made its debut in 2007, named after the street on which it resides . . . and for its corresponding nod to patriotic sensibilities. Fifteen years into its existence, the pub changed hands when it was purchased by Orange Umbrella Restaurants. Now, with a couple of years of operation under new ownership, Liberty Tavern has launched its first expansion at 2170 Polaris Parkway, the former address of Mellow Mushroom.