There has been a change in the median age at first marriage for both men and women in the United States, and the amount of change appears to be getting larger. In 2018, the median age at first marriage was almost 30 for men and almost 28 for women. While historically women married at an age that was three years younger than men, that gap has been slowly but steadily decreasing. Now they are only separated by two years, on average.
Here are the statistics from the U.S. Census Bureau of the median age at first marriage and a graph of the data going back to 1890.
According to the U.S. Census Bureau, the figures reported for 1947 to 1999 are based on Current Population Survey data. The figures for years prior to 1947 are based on decennial censuses. A standard error of 0.1 years is appropriate to measure sampling variability for any of the above estimated median ages at first marriage based on Current Population Survey data.
Impact of Legalization of Same-Sex Marriage
The legalization of same-sex marriage in mid-2015 may have resulted in raising the average age of first marriage in the years that followed. Long-committed couples were finally able to be legally wed. One survey in 2017 found that the average marrying age for male-male couples was 46 and for female-female couples was 36. However, the trend had been upwards for male-female couples for decades and there is no obvious change in that rate from looking at the graphs. As those long-committed couples take the plunge, the demographics of same sex couples getting married for the first time may come to resemble those of the general population.
The State of Marriage
Pew Research Center, "marriage continues to lose market share among Americans to other arrangements, such as cohabitation or living alone. According to census data cited in the report, barely half of adults ages 18 and older are married— 51 percent in 2010, compared with 72 percent in 1960. This decline is especially notable for young adults: 20 percent of 18- to 29-year-olds were married in 2010, compared with 59 percent in 1960. Associated with this trend is that the age at which men and women marry for the first time continues to rise to record levels."
It is notable that public attitudes about marriage are changing. Approximately 39 percent of Americans believe that marriage is becoming obsolete. Despite this, a majority of people who have never married say they would like to marry someday.
U.S. Census Bureau: Valentine's Day 2013: Feb. 14. Released by the U.S. Census Bureau's Public Information Office. 2/12/2013.
U.S. Census Bureau: Table MS-2. Estimated Median Age at First Marriage, by Sex: 1890 to the Present.
U.S. Census Bureau: Technical Documentation -- Current Population Survey.
U.S. Census Bureau: Annual Social and Economic Supplement: 2003 Current Population Survey -- Current Population Reports -- Series P20-553 -- America's Families and Living Arrangements: 2003 and earlier reports.