Wealth begets wealth. Just ask Alice Walton, who again ranks as the nation’s richest woman on the annual Forbes 400 list—her fourth straight year at the top, and 11th out of the past 12.

The only daughter of Walmart founder Sam Walton (d. 1992), she is $12 billion richer than a year ago on the back of a 10% hike in the retailer’s stock, amid e-commerce and membership growth and the expansion of ultra-fast delivery service. And Walton is only widening the gap between her and America’s second richest woman, Koch, Inc. heiress Julia Koch, whose fortune grew by $3.4 billion over the past year—but who is now $33.4 billion poorer than Walton, up from a $24.8 billion gap a year ago.

Overall, Walton, 76, ranks as the 13th-richest person in America, right behind her brothers Rob Walton (estimated fortune: $132 billion) and Jim Walton ($128 billion). Together the siblings, along with two heirs of their brother John........

© Forbes