The Commerce Department's third and final estimate of fourth-quarter GDP showed a 0.4 percent annual growth rate.
Economists had predicted it would be slightly better, at 0.5 percent.
The latest calculation was higher than the government's previous estimate of a 0.1 percent growth rate.
There was a big gain in business investment and higher exports of services, but growth was the slowest since the first quarter of 2011 and far from what is needed to continue to cut the US unemployment rate.
Recent data has shown the economy gathering strength. Retail sales have been stronger than expected, manufacturing output has picked up and employment growth has quickened, with the jobless rate dropping to 7.7 percent last month from 7.9 percent in January.
The number of Americans filing new claims for unemployment benefits rose more than expected last week, but probably not enough to suggest the labour market recovery was taking a step back.
Initial claims for state unemployment benefits increased by 16,000, to a seasonally adjusted 357,000. Despite the gain, they were in the middle of their range for this year.
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