Such was the case Thursday night, when a host of the city's top political, cultural and educational leaders celebrated a key milestone in the life of the Tsongas Industrial History Center, which grew out of the Lowell National Historical Park, Lowell School Department and UMass Lowell "partnership" 25 years ago. Reminiscing at the anniversary event, City Councilor William Samaras paid tribute to two men in launching the center: the late U.S. Sen. Paul Tsongas and the late school Superintendent Patrick Mogan.