Gross domestic product expanded at a 2.4 percent annual rate, the Commerce Department said in its first estimate on Friday, after an upwardly revised 3.7 percent growth pace in the January-March quarter.
Analysts polled by Reuters had forecast GDP, which measures total goods and services output within U.S. borders, growing at a 2.5 percent rate in the second quarter. The government had previously estimated a 2.7 percent growth rate for the first three months of this year.
"The anticipated slowdown in the economy is happening. Will business investment fall off a cliff next quarter if domestic consumer spending continues to flag?" said Lee Olver, managing director of financial strategies at Madison Williams & Co. in Houston.
The economy, which is digging out of its longest and deepest recession since the 1930s, has now grown for four straight quarters. However, growth has been too tepid, making little impact on a high unemployment rate.
The sluggish economy and a 9.5 percent unemployment rate are eroding President Barack Obama's popularity and dimming Democrats' prospects in November's mid-term elections. A Reuters-Ipsos poll this week showed only a 34 percent approval of Obama's handling of the economy and jobs compared to 46 percent who deemed it unsatisfactory. This is a sharp decline from early 2009, shortly after he took office, when more than half of those surveyed approved of Obama's handling of the worst financial crisis in decades.
In other economic news, a report showed that business activity in the Midwest was stronger than expected in July.
Growth in the last quarter was held back by a 28.8 percent surge in imports, which eclipsed a 10.3 percent rise in exports. The widening trade deficit lopped off 2.78 percentage points from growth, the largest subtraction since the third quarter of 1982. While the import surge subtracted from GDP, growing imports and robust business spending suggest strength in underlying demand.