<P> The Fortune 500 is an annual list compiled and published by Fortune magazine that ranks 500 of the largest United States corporations by total revenue for their respective fiscal years . The list includes publicly held companies, along with privately held companies for which revenues are publicly available . The concept of the Fortune 500 was created by Edgar P. Smith, a Fortune editor, and the first list was published in 1955 . The Fortune 500 is more commonly used than its subset Fortune 100 or wider list Fortune 1000 . </P> <P> The original Fortune 500 was limited to companies whose revenues were derived from manufacturing, mining, and energy exploration . At the same time, Fortune published companion "Fortune 50" lists of the 50 largest commercial banks (ranked by assets), utilities (ranked by assets), life insurance companies (ranked by assets), retailers (ranked by gross revenues) and transportation companies (ranked by revenues). Fortune magazine changed its methodology in 1994 to include service companies . With the change came 291 new entrants to the famous list including three in the Top 10 . </P>

How many original fortune 500 companies are there