Hundreds of union members and organizers descended on the streets of downtown Chicago on Monday morning to picket the offices of Goldman Sachs Inc. and Wells Fargo & Co.

The group, which included supporters from community group National People's Action and the Service Employees International Union, has organized the protests to coincide with the annual meeting of the American Bankers Association. The group is demanding that "banks end their over-reliance on greed and profits and commit to using their taxpayer bailouts and...