Wal-Mart heirs again top Forbes list of 25 richest U.S. families

The Walton family, which owns roughly a 50 percent stake in retailer Wal-Mart Stores Inc, was named the richest family in the United States for a third consecutive year on Wednesday, according to Forbes.

Others featured on Forbes' list include the Koch family, which owns the majority of conglomerate Koch Industries, the second largest private company in the United States. Their net worth was listed as $82 billion.

The Mars family, owners of the candy giant Mars Inc, was third riches with a net worth of $78 billion, according to Forbes.

Collectively, the top 25 wealthiest families in America are worth $722 billion, down 1.5 percent, or $11 billion, from a year ago.

Worth $130 billion, the Walton Family Foundation announced on Tuesday that it would commit $250 million to help urban charter schools gain access to more facilities.