What do you think of when you hear the phrase “old money?” Often, the term refers to families who have maintained wealth over generations, building massive fortunes in industries like steel, oil, railroads, and finance. Unlike the nouveau riche (new money), whose wealth is more recently acquired, “old money” dynasties have established legacies that stretch back to America’s Gilded Age.

From the Carnegie family to the Vanderbilts and Kennedys, here are 10 prominent American families whose fortunes have withstood the test of time, shaping not just their industries but the very fabric of U.S. society.

The Vanderbilt family’s wealth, which peaked at a staggering $185 billion (adjusted for inflation), was built by Cornelius “Commodore” Vanderbilt through shipping and railroads in the 19th century. Cornelius was a business tycoon who dominated the American transportation industry. In 1810, he borrowed $100 from his mother to start his business. Today, the family’s most famous descendant, Anderson Cooper (pictured with mom Gloria Vanderbilt), is a respected journalist and TV host.

Though much of the family fortune has diminished, the Vanderbilt name remains synonymous with New York’s social elite.

Andrew Carnegie, the Scottish-American industrialist, amassed his vast fortune in the steel industry. In 1892, he founded Carnegie Steel, which became the largest and most profitable industrial company of its time. At his peak, Carnegie’s wealth was estimated to be anywhere from $372 million to $300 billion (yowza!).