WASHINGTON — U.S. employers added 248,000 jobs in September, a burst of hiring that helped drive down the unemployment rate to 5.9 percent, the lowest since July 2008.

The Labor Department report this morning also showed that employers added 69,000 more jobs in July and August than the government had previously estimated.

The rate fell from 6.1 percent in August and is now close to 5.5 percent, which many economists consider a healthy level.

That could ratchet up pressure on the Federal Reserve to raise its benchmark interest rate earlier than it plans. Most economists have predicted that the Fed will do so in mid-2015.

The number of unemployed fell in September by 329,000 to 9.3 million. Most of them found jobs last month. But nearly 100,000 stopped looking for work. That exodus lowered the percentage of Americans working or looking for work to 62.7 percent, the lowest proportion since February 1978.