The inaugural issue of National Affairs, which aspires to succeed the late, great The Public Interest, has many articles available online. Example article: The evolution of divorce. The introductory material about the 70s is unsurprising:

Prior to the late 1960s, Americans were more likely to look at marriage and family through the prisms of duty, obligation, and sacrifice. A successful, happy home was one in which intimacy was an important good, but by no means the only one in view. A decent job, a well-maintained home, mutual spousal aid, child-rearing, and shared religious faith were seen almost universally as the goods that marriage and family life were intended to advance.

But the psychological revolution's focus on individual fulfillment and personal growth changed all that. Increasingly, marriage was seen as a vehicle for a self-oriented ethic of romance, intimacy, and fulfillment. In this new psychological approach to married life, one's primary obligation was not to one's family but to one's self; hence, marital success was defined not by successfully meeting obligations to one's spouse and children but by a strong sense of subjective happiness in marriage — usually to be found in and through an intense, emotional relationship with one's spouse.

On the other hand, the trends of subsequent decades are probably less widely known:

The figures are quite striking: College-educated Americans have seen their divorce rates drop by about 30% since the early 1980s, whereas Americans without college degrees have seen their divorce rates increase by about 6%. Just under a quarter of college-educated couples who married in the early 1970s divorced in their first ten years of marriage, compared to 34% of their less-educated peers. Twenty years later, only 17% of college-­educated couples who married in the early 1990s divorced in their first ten years of marriage; 36% of less-educated couples who married in the early 1990s, however, divorced sometime in their first decade of marriage.