U.S. Rep. Peter Roskam coasted to a fourth term on Tuesday, securing Illinois' 6th District against Democratic challenger Leslie Coolidge by a 19 percent margin, according to unofficial election results.

Coolidge called the Wheaton Republican to concede nearly four hours after the polls in Illinois closed. Roskam now will return to Washington, D.C., to try to help a fragile economic recovery and move past the partisan gridlock that has plagued Congress for the past two years.

"For the next two years, we will continue to work [to] turn the economy around as quickly as possible, to create jobs for the 23 million Americans currently unemployed, underemployed or who have simply given up looking for work," Roskam said in a statement.

Roskam easily secured his re-election bid against Coolidge in a redrawn 6th District that sprawls across five counties, including McHenry, Lake, Kane, DuPage and Cook. Coolidge, a retired accountant from Barrington Hills, had never previously ran a campaign.

Roskam, a key figure in the Republicans' effort to retake the U.S. House two years ago, greatly outmatched Coolidge, raising $3 million this election cycle compared to Coolidge's $244,200.

Roskam headily carried all five counties, amassing 20 to 30 percent margins in counties like Lake, Kane and DuPage, according to unofficial results. The official results won't be certified until days after Election Day.

Roskam was first elected to the 6th Congressional District in 2006, when he defeated Iraq war veteran Tammy Duckworth. She also won an election Tuesday,  taking the 8th Congressional District over Republican incumbent Joe Walsh.

While in Congress, Roskam has served on the influential Ways and Means Committee tasked with overseeing revenue and appropriation legislation in the U.S. House.

Coolidge campaigned on a solid Democratic platform, advocating for woman's rights, higher education and middle-class job growth. She appreciated the support from her Democratic base.

"It's been a rewarding experience, with the number of people who have been supportive with their time and enthusiasm," Coolidge said.