Most people do not know that prior to the mid-19th century, the government took very little interest in marriage and its termination in divorce.  These were mostly religious matters, and the states only began to take interest in the formalities when it came to deal with the spread of sexually transmitted diseases, specifically syphilis.  Shortly thereafter, states saw the licensing as a revenue stream, as well.  Prior to the advent of licensing, the choices were a religious ceremony or a common law arrangement without formality. 
Now, states provide for a civil license independent of the religious ceremony and many still honor a common law marriage if it meets time and circumstance conditions, such as a year of continuous cohabitation or some specified time together in the particular state.  Some states do not have a common law equivalent, although they will honor such if the couple comes from a state in which they met the criteria there. All states, under our Constitution, must give full faith and credit to the laws of all other states and, therefore, they must honor the legal marriage of one state in its borders if the couple was legally married elsewhere.
Assignment Question
Should the law be giving special consideration to the family at all?  States do vary, but all offer some special status to family and married couples, not all of which you may like.  For example, in some states, the physical assault of one spouse of another is called a family offense and not simply the crime of assault and battery. Likewise, the crime of rape outside a marriage is clearly written and prosecuted while within the marriage is somewhat nebulous in many states.  Should the laws be dealing with acts within the family differently than those outside the relationship?
In two to three pages, offer your thoughts, with examples.