The term "Black Friday" was originally used to describe the Sept. 24, 1864, stock market panic, but as early as the 19th century, shoppers have viewed Thanksgiving as the traditional start to the holiday shopping season, prompting celebration.

The holiday spree became so important to retailers that during the Great Depression, President Franklin D. Roosevelt moved Thanksgiving up to stretch out the holiday shopping season.

Newspapers in Philadelphia officially coined the term "Black Friday" in the late 1960s, using it to describe the rush of crowds at stores. There's also a belief that some retailers go from "in the red" to "in the black" for the year on that day.

Like last year, Target and some other stores are coming under fire for opening earlier for Black Friday. Some employees say they'd rather spend the Thanksgiving holiday with family, not at work.

Toy superstore Toys R Us is again leading the pack of early openings this year, announcing plans to open its doors at 8 p.m. on Thanksgiving night.

Not to be outdone, Wal-Mart, the world’s largest retailer, will also be offering discounts on toys, home accessories and clothing starting at 8 p.m. on Thanksgiving -- two hours earlier than last year.

After years of sticking to its guns and opening at 4 a.m. on Black Friday, Sears announced plans to open at 8 p.m. on Thanksgiving this year.

In perhaps the biggest change in Black Friday hours, Kmart is breaking its tradition of opening at 5 a.m. on Black Friday in favor of 8 p.m. on Thanksgiving night.

Target is opening its doors at 9 p.m. on Thanksgiving Day this year. That's three hours earlier than last year.

Best Buy's plan to open at midnight on Black Friday drew a protest petition from employees last year, but the electronics giant is sticking with those hours this year as well.

Macy's, which opened all of its 800-plus Macy’s stores nationwide at midnight on Black Friday for the first time last year, is doing so again this year.

Kohl's is also sticking with its midnight opening in 2012.

A record 226 million shoppers visited stores and websites over Black Friday weekend in 2011, according to the National Retail Federation. That's up from about 212 million the year before.

The average American spent $398.62 on Black Friday in 2011, with overall sales reaching an estimated $52.4 billion, according to the National Retail Federation.