🚀 go-pugleaf

I'm looking for information regarding the origin and basis of the 
concept of alimony or support payments.  The exact questions I am 
trying to answer are:

1) Where, in the marriage agreement, is the agreement made by the 
participants to support the other member in, or out of, the marriage 
for the rest of that person's life?  

2) If this agreement is made during the marriage ceremony, why does it 
supersede all other promises made in the marriage (fidelity, "love and 
honor," etc.)?  

3) If this agreement is not made in the marriage ceremony (example: 
the two parties "invent" their ceremony and do not include traditional 
"vows"), how is the law applied to that marriage�s separation?  Obviously, 
if the agreement is made on the marriage certificate application, this 
question is moot.

4) Are all states' marriage agreements identical?  If they are not, how does 
a different state's divorce law apply to the original marriage agreement?  
Is there federal legislation governing marriage and divorce?  Has the 
concept of alimony been tested in court?  If so, what are the benchmark 
cases?