People have been eager to talk about their age at marriage and other stats, but I'd like to know what makes your marriage work. I strongly suspect that when you got married will make a difference in the answer.
So, as one of the longest married (since 1976, when we were ages 19 and 24) I'll give you the traditional perspective. And it will be even more traditional than our 36 years of marriage might lead you to expect, because my husband and I both grew up in a conservative state, in a small-but-not-tiny town, and with a shared religious affiliation. The sexual revolution had happened by 1976, of course, but hadn't reached our town yet, so when we dated, there was still a strong dating culture in place -- the man asked and paid, sex before marriage was strongly discouraged, marriage was the goal of dating, and usually at relatively young ages, etc. Marriage was the way you became a grown-up and it was expected of everyone.
Divorce was very uncommon, but not unheard of, in our community. Both of our parents stayed married until our dads died in recent years. They didn't have perfect marriages, but they had figured out something that worked for them. Everything in our background led us to expect to get married while very young, to stay married, and to have a bunch of kids before we'd been married very long. We were still in school when our first baby was born in 1978. In short, what we had was the best of all possible worlds for making marriage work--strong community and family support from all sides.
Once, when we hadn't been married very long, a divinity student wanted to interview us about our marriage. I think she was quite taken aback at the conflicts we didn't have, which, as I thought about it, we had avoided because we shared many assumptions about marriage and our roles within it. People bristle at the thought of roles, but they are actually pretty helpful sometimes.
Now, I will add that we are both relatively congenial people (well, I know my husband is--I'll have to let my daughter pronounce on whether or not I am!) and we have always respected one another and worked to avoid conflict. One of our sets of parents had a traditional division of labor in marriage and one didn't, so we'd seen both sides of that, but the traditional division worked out best for us in terms of earning potential. (I have since had the opportunity to become waaaaaay overeducated, by the way.) I'd also have to say that we've been very, very blessed, which has of course contributed to our happy marriage.
As marriage supports and incentives have waned over the years, I'm pretty sure that many of you have not had such an easy path. I'd like to know what led you to marriage and how your marriage has been sustained.