Until very recently, New York was the only state in the US that would not grant a "no-fault" divorce, based on “irreconcilable differences” or other things you may have heard about.  In New York, in all cases filed prior to October 2010, you have to state in your divorce papers that your spouse did something wrong, making it unreasonable to expect you to continue to stay married to them.

A new law came into effect in October 2010 that permits a divorce action to be started based on the "irretrievable breakdown of the marriage" for a period of at least 6 months.  This ground is available for actions filed after October 2010.  This change has essentially brought "no fault" divorce option to New York.