I completely believe to answer this question honestly you must look at the different predominate cultures in America. Hispanic, White folk, Black folk.
Right of the top, marriage last longer in the Hispanic communities because most of them are Catholic and Catholics, as a rule, do not consider divorce. They also go through a pretty rigorous training before they get married. This is done to introduce them to the realities of married life and to allow each of them to participate in scenarios and conversations that uplift the union, shine light on some of the snags and snafu's, that can occur during married life.
White folk, many of which consider themselves Christian or Jewish, handle marriage in many ways, but mainly understand the economical benefit of marriage. Although getting married for "love" is the rally cry, getting ahead through marriage is the primary goal.
Black folk, the majority of them Christian, often opt out of marriage for varies reasons. Ironically, many of them have to do with finances. You often hear women say, "We don't have enough money to get married," and yes, they are usually living with the man. These folk are uninformed about the financial benefit of merging, in legal marriage with the man they are already sharing everything with.
Many claim to marry for love, black, white, or otherwise in this country; yet we bare the highest rate of divorce in the world. Marriage doesn't work in America, because we do not respect the benefits of married life. Most of us go into marriage, holding on to romance. It is a lethal combination, because once life hits the marriage (children, mortgage, jobs, parents, friends), and there is no true agreement (marriage), all bets are off.
Our way of thinking keeps us from truly sharing our lives. Women, tell the truth, many of you run to your friends, before you do your spouse. You use the excuse he doesn't understand you, but in reality, you don't really want him to because you don't want to give him something to use against you. Well, dear, until we unmask ourselves within our marriages, we cannot get what we want.
Men do the same thing. But I think men's desire to hold on to an image of themselves keeps them from really committing to marriage. May it be the computer nerd, the womanizer, the work-a-holic, so many of them are chasing the wrong things.
Marriage will not work in American until we truly decide to give our partners what they need. The only way that can be done is to open up and let them in. Make your marriage work, starting today. Agree to disagree. Listen to your spouses dreams. Smile at them. Show them love. Now is the time.