Alan Greenspan, who led the Federal Reserve through four presidencies, has died at age 100. The longtime Fed chairman passed away Monday morning at his home from complications of Parkinson's disease, according to a statement from his wife, NBC News chief Washington correspondent Andrea Mitchell.

For nearly two decades, Greenspan steered the nation's economy through periods of significant growth. He also navigated major crises, making decisions that rippled across financial markets and the broader economy.

Investors watched his testimony closely, parsing his dense economic language for clues about Fed policy. His measured tone made him a television fixture, with CNBC anchors dissecting his remarks for market implications.

Greenspan's tenure remains contested. Supporters credit his intellectual rigor and steady management of monetary policy. Critics point to his decisions during the housing bubble and the financial crisis that followed. Economists and policymakers will continue debating his legacy for years to come.