Revised figures from the US Commerce Department show GDP grew at an annual rate of 1.8 per cent in the period.
That was down from the previous estimate of two per cent and first estimate of 2.5 per cent.
The downward revision was largely due to lower consumer expenditure than previously thought.
Separate data showed a fall in weekly unemployment benefit claims.
Initial claims for state benefits dropped 4,000 to a seasonally adjusted 364,000, the Labor Department said - the lowest level since April 2008.