The holiday openings came despite threatened protests from workers' rights groups, which are opposed to employees working on the holiday instead of spending the day with family.
(Read more: 10 must-have gifts for gadget lovers)
Overall, the National Retail Federation expects retail sales to be up 4 percent to $602 billion during the last two months of the year. That's higher than last year's 3.5 percent growth, but below the 6 percent pace seen before the recession.
Analysts expect sales to be generated at the expense of profits, as retailers will likely have to do more discounting to get people into stores.
Here's how the start of the holiday shopping season is playing out. All times are EST, unless otherwise specified:
- Friday, 1:45 p.m.: Some avoid Black Friday and donate or get coats instead in Rhode Island.
While shoppers were spending Black Friday at the mall, some people in Rhode Island were taking a break from commerce to give away a coat or get one for free.
It's the state's twist on Buy Nothing Day, a two-decade-old statement against consumerism that started in Vancouver and is now marked on the day after Thanksgiving in some places in the U.S.
Greg Gerritt, an environmental activist from Providence, liked the idea of Buy Nothing Day but wanted to do something that gave back to the community. So he came up with the idea of having people donate a coat or get one for free. The state's Buy Nothing Day coat exchange is now marking its 17th year and has inspired similar events in Kentucky and Utah, Gerritt said.
This year, 15 sites were set up around Rhode Island for people to give or take a coat. The exchange on the lawn of the Statehouse went through a few thousand coats last year. Gerritt picked that site intentionally because it sits in the shadow of the Providence Place mall. He said he hopes the location will highlight the negative effects of consumerism on society.
Maureen Keane is unemployed and picked up four coats for friends as Christmas gifts. She says she can't afford gifts this year and calls it a wonderful program.
- Friday, 1:30 p.m.: J.C. Penney store manager feels encouraged after lackluster 2012.
Joe Cardamone, store manager of J.C. Penney's Manhattan store, said he's encouraged by the traffic and sales he is seeing. Penney spokeswoman Daphne Avila said the chain saw similar crowds at other locations across the country.
A year ago, Penney didn't open until 6 a.m. Friday. That made the retailer one of the laggards for the unofficial kickoff to the shopping season. It also cobbled together a few deals at the last minute. This year, most stores opened at 8 p.m. Thursday.
"It felt like getting back to the old times," Cardamone said. "Last year, it was heartbreaking because we were never in the game."
He added that he saw new customers and once-loyal ones who hadn't been back for a while.
The encouraging signs come as Penney is trying to recover from a botched transformation plan spearheaded by Ron Johnson, who was ousted as CEO in April after 18 months on the job.
Penney brought back Johnson's predecessor, Mike Ullman, as CEO. He is restoring frequent sales and basic merchandise that were eliminated as Johnson aimed to attract a more affluent, younger shopper.
- Friday, 1:20 p.m.: Black Friday shoppers at some stores in Newark, Del., were left in the dark briefly.
The Christiana Mall had a partial power outage, though many stores still had power.
Delmarva Power said a fuse problem with the mall's electrical system caused the outage. Full power was restored in less than an hour. During the outage, some storefronts pulled down security gates. There was also an increased police and mall security presence.
- Friday, 1:05 p.m.: Most deals not worth the hassle for Georgia couple
Tony Abruzzio was at a Best Buy store in Savannah, Ga., to get $230 off a laptop for his college-student daughter.
Otherwise, Abruzzio and his wife, Sherry, were more interested in avoiding big crowds than scoring savings on Black Friday. They aborted an attempt to buy gifts at Savannah's Bass Pro Shop when they saw what looked like at least 100 people waiting for cashiers.
"I just put our stuff back," Abruzzio said. "We didn't want to stand in line all day."
(Read more: Black Friday arrests at Wal-Mart wage protest)
Sherry Abruzzio said she tends to do much of her Christmas shopping online and finds she gets better deals if she waits until mid- to late-December.
"I do most of it right before Christmas because by then they're trying to get rid of their inventory," she said.
- Friday, 12:55 p.m.: Online sales live up to promise on Thanksgiving, according to preliminary data.
E-commerce sales rose 20 percent on Thanksgiving compared with last year, according to IBM Benchmark, which tracks e-commerce sales for 800 retailers. Still, heavy discounting and shoppers' use of coupons depressed the dollar transactions. The number of items shoppers threw in rose 1 percent, but the average order size slipped 2.5 percent to $127.59.
Growth was moderate in the morning and afternoon on Thanksgiving, at about 10 percent. It then surged at 8 p.m. when many merchants opened their physical stores for shopping and posted new Black Friday promotions on their sites.
"We are definitely seeing savvy shopper benefit from early discounting that stores are doing," said Jay Henderson, strategy director for IBM's Smarter Commerce.
IBM also said traffic from mobile devices accounted for 43 percent of all online traffic on Thanksgiving, up from 32 percent a year ago.
Meanwhile, Wal-Mart said mobile accounted for 53 percent of total traffic to Walmart.com on Thanksgiving, the highest to date. That figure averaged 40 percent during last year's holiday season. On Thursday, mobile traffic on Walmart.com peaked at 7 p.m.
- Friday, 12:45 p.m.: Black Friday—and its problems—aren't limited to the United States.
At least one person has been injured in Northern Ireland as shoppers rushed to get their hands on deals for Black Friday, a day of sales modeled on the American kick-off to the holiday shopping season.
British supermarket chain Asda—owned by U.S. retail giant Wal-Mart— has been advertising its Black Friday deals throughout the U.K.
The Northern Ireland Ambulance Service said it was called to Westwood Center in Belfast and took a woman with an arm injury to the hospital.
Asda's Westwood store had two dozen 32-inch TVs on sale at reduced prices, according to Britain's Press Association.
Asda said in a statement that the safety of its customers is of "vital importance" and that it has extra security teams in stores.
- Friday, 12:20 p.m.: In an interview, Macy's CEO says employees chose Thanksgiving shifts.
Like many other retailers, Macy's began offering deals on Thursday. Some workers' rights groups threatened protests at various retailers.
Macy's CEO Terry Lundgren said the company could have filled spots with temporary workers, but about 90 percent were filled by regular employees. He said the company gave first choice to its 176,000 full-time workers. Many were willing, he said, partly because of overtime pay.
"They preferred 8 to midnight," he said Friday morning. "They get time and a half and finish at 4 a.m. and are ready to go shopping with their friends."
In the Friday morning interview, Lundgren also said the overall holiday season was "so far, so good."
"There were more customers this year than last year," he said, adding that it remains to be seen whether that pace will continue.
In terms of online sales, demand was similar online and in stores, Lundgren said.
"Customers are starting their shopping journey on their phone, but they want to touch the cashmere and try on the shoe and boot to make sure it's just right," he said.
- Friday, 11:55 a.m.: Slow going in Tulsa, Okla., as mall opens early.
Suhail Zaidi, owner of a Bags and Bangles accessory store at the Woodland Hills Mall in south Tulsa, said Black Friday so far had been "slow motion."
Zaidi said he'd seen only about 20 customers by mid-morning Friday. Although the mall opened at 8 p.m. CST Thursday, compared with 5 a.m. CST Friday last year, he had seen the same amount of customers so far. Most of the customers who did purchase jewelry were buying small, lower-priced items.
Zaidi wasn't a big fan of opening earlier, but he said mall policy required that he do so.
"We opened up too early," he said. "We ruined the holiday."
Zaidi said the mall and his booth had been somewhat busy Thursday evening but it died down by 3 a.m. CST. "For me, Black Friday is a good shopping day, but opening up on Thanksgiving is ridiculous."
Woodland Hills will stay open until 10 p.m. CST Friday.
Jim Miller, 63, was one of about a dozen people sitting at the mall's food court and said he was surprised by the turnout.
"I thought there would be a bigger crowd than this—unless people came yesterday," he said.
- Friday, 11:35 a.m.: A dummy holds place in line for Anchorage shopper.
Annie Luck's Black Friday started Wednesday and included a mannequin.
The 53-year-old Anchorage woman set up a lawn chair at 4 p.m. Wednesday, local time, to stake out first place in line for the opening of Best Buy 26 hours later. She spent part of Wednesday night sleeping in her car. A dummy in a face mask and construction hat held her place.
The Anchorage Daily News reports Luck wore five pairs of pants and five shirts to stay warm in 16-degree temperatures.
Luck was shopping for three teenage sons. She figured she could save $1,100 by getting to the store early for two laptop computers and three iPods.
Luck says she wished she could have been home to cook Thanksgiving dinner but she's "going with the flow now."