Following graduation, he and Linda moved to Knoxville where Pete joined the Tennessee Valley Authority as an attorney, and subsequently as Assistant General Counsel for Environment and then a division director, after which in 1979 he became a loaned executive to the 1982 World’s Fair where he was Vice President in charge of the legal department, leaving that position at the beginning of 1983 with the wrap-up of the fair corporation.
In 1985 he established Gulf & Ohio Railways of which he now serves as Chairman. Gulf & Ohio owns and operates four railroads in the Southeastern United States, including one in Knoxville and Knox County. By 1998 Gulf & Ohio had acquired considerable locomotive rebuilding experience and it spun off Knoxville Locomotive Works, of which Pete is Chairman, and which produces low emission and battery powered locomotives.
Locally Claussen is the founder and Chairman of the Seven Islands Foundation that donated most of the property that became Tennessee’s 56th State Park, the Seven Islands State Birding Park. He also has served as Chairman of Child and Family Services, the Public Building Authority, Zoo Knoxville, and as a member of the Legacy Parks and Museum of Appalachia boards.
In Nashville he has served as Chairman of the Tennessee Chapter of the Nature Conservancy board, and as a member of the Tennessee Conservation Commission and currently serves as a member of the Tennessee Heritage Conservation Trust Fund board.
In Washington DC he has been Chairman of the American Short Line and Regional Railroad Association Legislative Policy Committee and a member of its Executive Committee. He is one of ten living members of the American Short Line Railroad Hall of Fame. He also has been a member of the National Portrait Gallery board, and has been Chairman of the Advisory Board of the Smithsonian National Museum of American History, which houses the Linda and Pete Claussen Hall of Democracy. He also has been a member of the Smithsonian National Advisory Board and currently is a member of both Smithsonian Alumni boards.