In 1974, Minnesota enacted a no-fault divorce law. This law deleted the specific grounds for divorce that needed to be proven before a couple could dissolve their marriage. The law didn't eliminate fault as a consideration for division of property or alimony (this has since been changed to a no-fault status as well, although Minnesota courts have latitude in allocating financial consequences for 'bad behavior'). In enacting this law, legislators were following the lead of numerous other states who were rewriting their divorce laws.
Dating back to before the 20th century, anyone wanting a divorce in Minnesota would have to prove that one spouse was guilty of one or another of a list of grievous offenses toward the other spouse. The concept of a no-fault divorce was actually pioneered by the Bolsheviks; subsequent to the Russian Revolution, the Bolsheviks passed a Divorce Decree in 1918 that removed all church-driven moral judgments from legal affairs. In the United States, California was the first state to enact no-fault legislation. New York was the last state to become no-fault, waiting until 2010 to pass such legislation (prior to this change, New Yorkers needed to be legally separated for a year before a divorce was granted).
It should be noted that to this day, there are arguments both for and against no-fault divorce within the women's rights movement. Arguing for no-fault divorce are those who say that domestic violence and female suicide rates are lower with no-fault divorces and that prior to these laws, many women were economically and emotionally powerless to prove their spouses guilty of bad behavior. Additionally, lawyers complained about the 'legal fictions' that many couples created to justify divorces, using valuable court time and money. Arguing against no-fault divorces are those who say that fathers' rights are being curtailed with a presumption of child custody toward the woman, even if he has done no wrong. Also, some women argue that no-fault divorce takes away any bargaining leverage from the non-moneyed spouse. Lastly, there are those who argue that no-fault divorce devalues marriage to the point of no longer being a contract.