It's 'Equal Pay Day' today, and President Obama marked the occasion at Sewall-Belmont House and Museum in Washington, D.C.
He designated it a new national monument as the home that has been central to the women's rights movement.
Equal Pay Day symbolizes when a women's income catches up to what men were paid in the previous year.
On average, women earn 79 cents for every dollar earned by their male co-workers.