Sixty-seven women appear on the latest Forbes 400 list of America’s wealthiest people, released earlier in October. They account for 17% of the list and have a combined net worth of $839 billion. In compiling the new list, researchers met in person or spoke virtually or by phone with each one when possible, and interviewed their employees, handlers, asset managers and financial advisors, rivals, peers and attorneys. They also examined Securities and Exchange Commission documents, court filings, probate records and news articles. They took into account all types of assets, and factored in debt and charitable giving. To determine how philanthropic each Forbes 400 member has been, Forbes looked into their known charitable giving and assigned each a philanthropy score from 1 to 5. A majority of the billionaires on the list scored a 1 or 2, meaning they have given less than 5% of their fortune to charity. See the accompanying gallery for the 20 wealthiest women in the United States. Their net worths are as of Sept. 1.