In the USA a number of states are de jure community property states. In those states, assets acquired in marriage, and appreciation in value of assets owned before marriage are both considered to belong equally to both spouses.
Many other states are de facto community property states. There is often some sort of "equitable" division of assets in a divorce. In practical terms this often appears quite similar to the de jure states.
One of my favorite quips was from Tom Arnold, during his second divorce. He said something like "she wants half of half of Roseanne's money".
Can the members of the marriage(spouses?) change that?
Here in Spain some autonomous communities (like the states in USA) have community property as default and some others have asset separation as default but when one gets married can decided which one to use
You can get a prenuptial agreement (prenup), but which laws you are allowed to override varies by state, duration of the marriage, the whims of the divorce court, and how diligent you are about keeping assets separate during the marriage. You're probably better off spending your energy on avoiding marrying the wrong person...
Many other states are de facto community property states. There is often some sort of "equitable" division of assets in a divorce. In practical terms this often appears quite similar to the de jure states.
One of my favorite quips was from Tom Arnold, during his second divorce. He said something like "she wants half of half of Roseanne's money".