For those who married for the first time between 20, about six-in-ten Hispanic men (62%) could expect their marriages to last at least 20 years, compared with 54% of white men and 53% of black men.
Another factor linked to long-lasting marriages is whether couples live together before tying the knot.
For Asian women who were married for the first time between 20, the chance that they may celebrate their 20-year wedding anniversary is nearly 70%.
By contrast, about half of Hispanic and white women may see their marriages last that long. Among men, Hispanics have the highest likelihood of being in a long-lasting marriage (findings about Asian men are not included because the sample size was too small to be nationally representative).
In addition, men with a higher level of education are more likely to get married in the first place when compared with less-educated men.
There also are distinctive patterns in marriage longevity by race and ethnicity.
The probability of a lasting first marriage is derived from marital history data from the National Survey of Family Growth, a nationally representative sample of women and men who were ages 15 to 44 between 20.
Estimates are based on an approach similar to that used to determine life expectancy and assume that marriage patterns in the future will follow patterns today.
In short, couples who lived together before getting married had a slightly lower chance of having a long-term marriage than those who did not live together.
Among women who did not live with their spouse before getting married for the first time, 57% can expect to still be married after 20 years.
"This would provide indisputable guidance which would be hugely helpful, rather than having to establish precedents through the courts." The Free Church wants "some reassurance that in the eyes of the state it will still be legal to believe that marriage is between a man and a woman, that those who hold to this traditional view will not be subject to prosecution and that they will be free to express their opinions", the spokesman said.
It said: "Given what has already happened in England - where a court case is being brought against the Church of England with the ink barely dry on the Royal Assent - there is no doubt that we will see similar instances north of the Border.
While more-educated women have the highest chances for a long-term marriage, college-educated men also stand out.