When Jerome Powell was sworn in as chair of the Federal Reserve eight years ago, economists worried that inflation and interest rates were too low and that too few Americans had jobs. Now, as Powell steps down after eight tumultuous years atop the Fed, the U.S. economy is transformed. Along the way, Powell shrugged off relentless personal attacks from President Donald Trump that began just months after his appointment. But in January, he pushed back against an unprecedented legal investigation by the Justice Department, becoming one of the few top officials in Washington to stand up to the Trump White House. His success at protecting the Fed’s independence from day-to-day politics will be a key part of his legacy.