Am going to say this as blunt as it comes. Sorry to say this and no harm intended, but most Americans lack cultures and values. They are very much sentimental. They only believe in what is right and wrong, and do not hesitate to express theirselves and emotions regardless of what people or society think or say about them. This is what them sets them apart from other cultured regions like africans.
Africans care too much what society thinks about them. I won't say it's the right behavior as it might very well lead to unhappiness, but to an extent, it has thought us how to be patient, endure, forgiven and tolerate one another, the key to having a successful marriage. I can't say if most Americans lack these attributes, but I can definitely say they don't put as much effort as africans and it's probably why there's high rate of divorce in America.
Another thing i've come to understand is that though divorce is a difficult process, i think divorce in America comes with certain benefits like properties and mostly cash which are often divided in certain percentage to the spouses. In my country, divorce doesn't work that way, instead it leaves you with a scar visible for societal critism, this especially affects the women who find it hard remarrying.