One law split America's banks in two for 66 years, then vanished

After the 1929 crash, the 1933 Banking Act's Glass-Steagall provisions forced commercial banks (which held deposits) and investment banks (which underwrote securities) to become separate companies, blaming the mix for reckless pre-crash lending. Congress repealed the separation in 1999 via the Gramm-Leach-Bliley Act, and economists still argue over whether that repeal helped set up the 2008 crisis.

— Carter Glass and Henry B. Steagall (sponsors); U.S. Congress, Glass–Steagall legislation — Banking Act of 1933; repealed in part by the Gramm-Leach-Bliley Act, 1999