All of Standard & Poor's services grew out of Henry Varnum Poor's original 1860 financial compilation, "History of the Railroads and Canals of the United States," and his subsequent railroad manuals. The S&P 500 was initially introduced in 1957, after Poor's Publishing was merged with Standard Statistics in 1941.
The joint company began publishing Bond Guides almost immediately after the merger. "The Bond Guide" was a major source of investment information in its time, giving statistics and quality ratings for a range of corporate bonds. While the Second World War impeded growth, by 1946, Standard & Poor's was thriving. It was among the first companies to use the IBM electronic punch card system, buying one to organize the massive amounts of data it held on America's companies.
This electronic data, and the upgraded systems that followed the first IBM setup, allowed the company to launch the hourly reports on the top 500 stocks that formed the S&P 500. Newspaper reports of the time heralded it as an electronic index to serve the market. While the S&P 500 features the most commonly held stocks in the U.S., it was joined in 1994 by the S&P SmallCap 600 Index, which along with the S&P MidCap 400, creates the S&P 1500, a broad market overview of equities across all types of company.
Standard & Poor's has been owned by McGraw-Hill since 1966, and it began global expansion between 1984 and 1986 with offices in London and Tokyo.