Nation Rings In Season of Spending : Shopping: Day after Thanksgiving finds hordes of Americans hungry for holiday bargains.

Customers clutching credit cards and wish lists joined by children eager for a glimpse of Santa Claus crammed into stores around the country today in the traditional start of the post-Thanksgiving buying spree.

Old-fashioned holiday spirit mixed with a hunger for bargains sent shoppers and browsers out in force, promising to produce a day worthy of its billing as the busiest one of the year for merchants.

The six B. Altman & Co. department stores in New York, New Jersey and Pennsylvania that are closing down--financially struggling parent company Hooker Corp. couldn’t find a buyer for the chain--drew hordes of people to their liquidation sales.

The crowd clamoring to get inside B. Altman’s main store in Manhattan was so heavy that shoppers had to be admitted in shifts.

“We’re having an unbelievable day,” said Brenda Smith, secretary for the manager at Altman’s in Short Hills, N.J.

Other store managers in many areas reported customers lined up outside waiting for doors to open, a hopeful sign in the most crucial season of a year that so far has been slow for retailers.

At Bloomingdale’s department store in Manhattan, customers lined up early in numbingly cold weather to get a jump on their holiday shopping, and surged inside when the doors opened at 9 a.m.

“We’re filling up with people rapidly,” Bloomingdale’s spokeswoman Ann Stock said. “As always, we expect this to be the busiest day of the year.”

Early shoppers at Bloomingdale’s grabbed mittens, gloves, scarfs and hats. Others made a beeline for the coat department. New York’s first Thanksgiving snowfall in 51 years combined with sub-freezing temperatures apparently put people in the mood to buy warm clothing.

Shoppers streamed into suburban malls and downtowns nationwide hoping to get as much gift buying done as possible at the start of the peak shopping season. Big markdowns on merchandise at some troubled stores lured bargain-hunters while shoppers elsewhere scanned the aisles for hard-to-find items, such as the popular Nintendo video games.

The Santa Claus at Crabtree Valley Mall in Raleigh, N.C., said most of the several dozen children that had confided their requests to him this morning asked for Nintendo items.

Operators of Southern California malls extended their hours today, but found shoppers already waiting when they opened for business.

“There were people waiting for us to open when I got here at 7:20 this morning, even though we weren’t going to open until 8,” said Clair Griffith, general manager of the 180-store Puente Hills Mall in the City of Industry in eastern Los Angeles County.

Elsewhere in the region, parking lots were jamming up early.

“The day after Thanksgiving and the day after Christmas are the two days each year that we fill up the lot,” said Nora Levy, marketing director of the 140-store Santa Anita Fashion Park in Arcadia, which has 5,200 parking spaces.