What was the first company with a $1 billion market cap?
Answer: United States Steel Corporation
According to Investopedia the United States Steel Corporation was the world's first company to surpass the market capitalization mark of $1 billion dollars. In the early 20th century, John Pierpont Morgan (J.P.) set his sights on the steel industry. With the help of Charles Schwab, the two convinced Andrew Carnegie to sell his business for an overall price of roughly $492 million in stocks and bonds, and U.S. Steel was born.
In 1901, Morgan issued $303 million in mortgage bonds, $510 million in preferred stock, and $508 million in common stock – creating a total capitalization of approximately $1.4 billion - on a company with real assets of $682 million. Thus, half of its worth was goodwill, but the public bought into the overvalued securities.