When the Department of Justice and Federal Trade Commission announced broad antitrust investigations of Facebook, Apple, Amazon and Alphabet in July, they brought a relatively dormant area of American law back into the spotlight.
Antitrust law has existed in the United States since 1890, but it hasn't seen so much attention since the Microsoft case in the late 1990s.
Watch this video to find out how antitrust law has evolved in its 130-year history and what it means for America's biggest businesses today.