The Federal Reserve is taking what may be the first significant step toward launching its own virtual currency, a move that could shake up banks, give millions of low-income Americans access to the financial system and fortify the dollar's status as the world's reserve currency.

The idea of creating a fully digital version of the U.S. dollar, which was unthinkable just a few years ago, has gained bipartisan interest from lawmakers as diverse as Sens. Elizabeth Warren (D-Mass.) and John Kennedy (R-La.) because of its potential benefits for consumers who don't have bank accounts. But it's also sparking strong pushback from those with the most to lose: banks.