A Class 1 railroad is defined as any railroad with annual revenue of more than $504,803,294 (the 1992 threshold of $250 million, set by the ICC, adjusted for inflation). There are six Class 1 Railroads operating in the United States; BNSF, CSX, CN, CPKC, NS and UP. Founded in 1859, Santa Fe was one of the largest railroads in North America up until 1996, when it merged with Burlington Northern to form BNSF.