Topping this year’s list was Exxon Mobil Corp., followed by Wal Mart Stores Inc. Exxon regained the top spot on the list due to its acquisition of XTO Energy Inc., which has allowed the oil giant to become a natural gas titan as well through the controversial technique of fracking, according to Fortune.

Fortune ranked Principal Financial Group Inc. at 295, with revenues of $8.7 million, Casey’s General Stores Inc. at 473 with $5.1 million in revenues, and Rockwell Collins Inc. at 496 with revenues of $4.8 million. Omaha-based Berkshire Hathaway Inc. ranked seventh in this year’s list.

Big oil took the top spots in the list, with Exxon, Chevron Corp. and ConocoPhilips all in the top four. 

Although unemployment in the United States is still relatively high at 8.1 percent and Congress continues to cut back to balance the federal budget, the Fortune 500 companies posted the biggest combined profit in the history of the list at $824.5 billion, according to CBS, and a 16 percent increase in profits over last year. The previous record was set in 2006 at $785 billion. 

“Businesses are doing well,” said Andy Serwer, managing editor of Fortune, in an interview with CBS.  “They’ve really come out of the downturn, doing things right. They’re in good shape. A lot of that has to do with the fact that they’ve cut back. They’ve cut costs during the downturn. meaning layoffs, quite frankly. That’s why profits are so high.”