Although national marriage statistics are unavailable, a study of 18 states that do keep marriage records revealed that more couples are opting for a civil marriage ceremony rather than having a religious ceremony.

Cathy Lynn Grossman and In-Sung Yoo, in a USA TODAY article, report that "University of Washington sociologist Pepper Schwartz, author of American Couples, cites high divorce and remarriage rates, more interfaith marriages and more personalized ideas on spirituality" as some of the reasons for the rise in civil marriages.
Marriage Statistics