The U.S. unemployment rate fell to 7.8 percent last month, dropping below 8 percent for the first time in nearly four years and giving President Barack Obama a potential boost with the election a month away.

The rate declined from 8.1 percent because the number of people who said they were employed soared by 873,000 — an encouraging sign for an economy that’s been struggling to create enough jobs.

The number of unemployed Americans is now 12.1 million, the fewest since January 2009.

The Labor Department said employers added 114,000 jobs in September. It also said the economy created 86,000 more jobs in July and August than the department had initially estimated.

Wages rose in September. And more people started looking for work.

The revisions show employers added 146,000 jobs per month from July through September, up from 67,000 in the previous three months.

The 7.8 percent unemployment rate for September matches the rate in January 2009, when Obama took office. In the months after Obama’s inauguration, the rate rose sharply and had topped 8 percent for 43 straight months.

The decline in the unemployment rate comes at a critical moment for Obama, who is coming off a weak debate performance this week against GOP challenger Mitt Romney.

The September employment report may be the last that might sway undecided voters. The October jobs report will be released only four days before Election Day.