In Maryland, men who work full time make an average of $140 more per week than women, according to data compiled by the congressional Joint Economic Committee. Nationally, the pay gap is even greater, at $148.

Over the course of a year, that's a nearly $7,700 difference in wages.

In an effort to close the income gap in Maryland and across the country, U.S. Sen. Barbara Mikulski (D-MD) is busy promoting the Paycheck Fairness Act, scheduled for a Senate debate on Tuesday.

In a telephone conference call with the press, Mikulski said the act advances pay equality beyond measures established in the Equal Pay Act of 1963 and the Lily Ledbetter Fair Pay Act, the first piece of legislation signed by President Barack Obama when he took office in 2009.

The Ledbetter Act allows female employees to sue employers for back pay. The Paycheck Fairness Act would also allow them to seek punitive damages and would prohibit employers from retaliating against them for sharing salary information with coworkers.

"American women are mad as hell," Mikulski said. "They're ready to fight."

Valerie Jarrett, senior adviser to Obama, said, "We're committed to the basic idea that equal pay for equal work is not a luxury, it's a necessity."

"You have the President's full support," Jarrett told Mikulski on the call.