NEW YORK — Warren Buffett’s Berkshire Hathaway Inc. on Tuesday agreed to buy Burlington Northern Santa Fe Corp., making a $34 billion bet on the future of the U.S. economy.

Burlington Northern, the second-largest U.S. railroad, is the biggest hauler of food products like corn and coal for electricity, making it an indicator of the country’s economic health. The railroad also ships a large amount of goods from Western ports including everyday items such as refrigerators, clothing and TVs.