The U.S. economy was battered even more than first suspected by the harsh winter, actually shrinking from January through March. The result marked the first retreat in three years, but economists are confident the downturn was temporary. According to the Commerce Department, gross domestic product contracted at an annual rate of 1% in the first quarter. That was worse than the government's initial estimate last month that GDP during the period grew by a slight 0.1%. The economy last posted a decline in the first three months of 2011 when it dropped 1.3%.