Ms Schapiro is one of America's most experienced regulators
The US Senate has approved President Barack Obama's choice of Mary Schapiro to head the financial watchdog, the Securities and Exchange Commission.
Correspondents say her priority will be to restore investors' confidence amid the worst financial crises in decades.
Confirmation of the Treasury Secretary, Timothy Geithner, is expected on Monday, Democratic Senate leaders said.
A panel cleared the way for his full nomination despite concern he failed to pay his taxes on time some years ago.
Mr Geithner appeared before the Senate Finance Committee to apologize for what he called "careless mistakes" in failing to pay $34,000 in taxes he owed until shortly before he was nominated.
Mr Geithner, who now heads the New York Federal Reserve Bank, was considered by many to be an ideal candidate for the job because he has already been deeply involved in government efforts to prop up financial institutions and markets.
He answered dozens of written questions from senators in a 102-page document released on Thursday, reaffirming the Treasury's long-standing policy that "a strong dollar is in America's national interest".
He also issued a stern warning to China, saying Mr Obama believes Beijing is "manipulating" its currency, using a term the Bush administration had deliberately avoided for years to describe Beijing's foreign exchange practices.
The comments drew a response from China, which has a large trade surplus with the United States.
A Chinese central bank official said that the bank had noted Mr Geithner's comments and reported them to relevant Chinese government departments.
Mr Geithner also said the Treasury had no current plans to request more bailout money beyond the $700 billion already authorized, but that the situation was "dynamic."