(MONEY Magazine) – When the Census Bureau released a landmark study of wealth in America in late July, the principal findings grabbed headlines: the median net worth of white households, at $39,135, was roughly 12 times greater than that for blacks, at $3,397. Beyond those stunning statistics, however, the study also provided a fascinating picture of how Americans become wealthy. Yes, it helps if you are born white. But it takes much more than that. The underlying factors include age and education, income and history and, almost as significantly, getting and staying married. Not surprisingly, older and better-educated people are more likely to be wealthy than are younger, less highly schooled ones. The median net worth of households headed by college graduates, for example, was $60,417; for high school grads, $31,892; and for those with less than 12 years of education, $23,447. The lesson, as this month's special report on page 132 explains, is that education is a great investment. Flowing from education is a healthy income -- another ticket to wealth. Fully 38% of the nation's total net worth, which for the Census Bureau's purposes included home equity, bank accounts, automobiles and securities, is controlled by the 12% of households that have monthly incomes of $4,000 or more. Small differences in income create big differences in wealth, largely because whatever is left after the essentials are paid for can become assets that grow exponentially over time and ultimately can be passed from generation to generation. Largely because of discrimination, blacks have earned much less than whites historically; that is the main reason why the wealth gap between them is so great. Right now, blacks earn about $6 for every $10 that is taken home by whites. Another key to wealth is marriage. When the net worth of married couples is compared across racial lines, the wealth gap narrows dramatically -- to about 4 to 1 between whites and blacks and 5 to 1 between whites and Hispanics. It's not so much that two can live cheaper than one, but that two can earn more than one. Excess earnings often become savings and then wealth. Overall, households headed by married couples had a median net worth of $50,116, compared with $13,885 for households headed by unmarried females (whose numbers include large numbers of wealthy widows as well as unwed mothers on welfare) and $9,883 for those headed by unmarried men. The message, with apologies to Henny Youngman: don't take my wife -- or husband -- please.