"I simply cannot allow partisan politics to stand in the way of the basic functioning of government," Obama said in a statement.
Both Republican and Democratic presidents have made recess appointments, which circumvents the Senate's authority to confirm nominees, when they could not overcome delays in the Senate. President George W. Bush made more than 170 such appointments in his two-term presidency. President Bill Clinton made nearly 140.
Obama had been on record as warning of recess appointments if the Senate didn't act. He followed through at the end of a week in which his political standing was significantly bolstered by the party-line passage of a historic health care bill, a student loan overhaul and a hard-fought nuclear arms treaty with Russia.
The White House dropped the news in a press release on a quiet Saturday, with Obama at Camp David and lawmakers home in their districts.
The recess appointments mean the 15 people could serve in their jobs through the end of 2011, when the next Senate finishes its term. A recess appointment ends at the completion of the next Senate session or when a person is nominated and confirmed to the job, whichever comes first.
The appointees include the contentious choice of union lawyer Craig Becker for the National Labor Relations Board. Republicans have held up his confirmation for months, saying they fear he would circumvent Congress to make labor laws more union-friendly.
Democrats had failed to overcome Republican delaying tactics on Becker's nomination, and all 41 GOP senators wrote to Obama on Thursday urging him not to appoint Becker over the break - to no avail.
The White House says the appointees have been awaiting a vote for an average of seven months.
