The government shutdown in October did little to slow import volume at the nation's major retail container ports, according to the National Retail Federation (NRF), a Washington, D.C.-based trade group. In fact import volume grew 6.5 percent in October when compared with the previous year.

NRF's Global Port Tracker covers the ports of Los Angeles/Long Beach, Oakland, Seattle and Tacoma on the West Coast; New York/New Jersey, Hampton Roads, Charleston, Savannah, Port Everglades and Miami on the East Coast; and Houston on the Gulf Coast.

"Retailers typically place their orders for merchandise months ahead of time, so cargo arriving at the ports in October and for most of the rest of the year was ordered long before anybody ever heard of a shutdown," said NRF Vice President for Supply Chain and Customs Policy Jonathan Gold, in a statement.

NRF said that some some government workers involved with clearing cargo were furloughed during the 16-day goverment shutdown, but U.S. Customs and Border Protection inspectors remained on the job and no major disruptions of cargo handling were reported as a result.

NRF has predicted that this year's holiday sales will increase 3.9 percent over 2012 numbers to total $602 billion. The federation said cargo import numbers do not correlate directly with sales because they count only the number of cargo containers, and not the value of the merchandise inside them.

Still, most the the holiday season's merchandise is brought into the country in August, September and October. The 4.35 million cargo containers handled during that period represent a 4.3 percent increase over last year and account for about 27 percent of all retail imports for the entire year, NRF said.