U.S. President Obama on Monday called for more work to be done to close the wage gap for women in the workplace, marking the 50th anniversary of the U.S. Equal Pay Act. \"So this is the 21st century. It\'s time to close that gap,\" said the president at an event in the White House commemorating the landmark legislation on equal pay. \"The day that the bill was signed into law, women earned 59 cents for every dollar a man earned on average. Today, it\'s about 77 cents,\" said the president, adding that the progress was far from enough. \"But as long as this gap persists, we\'re going to have more work to do. And now is the time to keep up the work that all those trailblazers started 50 years ago,\" he said. Obama noted that a latest report found that women are now the primary source of income for nearly 40 percent of American families.