The short answer to your question: No.
Explanation: There were once two ways to become married, either by common law or by actually getting a marriage certificate. What you are talking about is common law marriage, in which if a couple lives together long enough (usually 7 years) and during that time hold themselves out as husband and wife, such as by sharing a last name, filing a joint tax return, etc. after a set number of years they will be married under common law, and therefore be subject to all of the laws which apply to married people (i.e. such as having to actually file a divorce decree to become divorced, spousal inheritance laws kick in, etc). No states let people become married by common law anymore as all states now require a marriage license to recognize the marriage. However, some states still recognize common law marriage so long as the time period was met on or before the year that the state abolished common law marriage (for a good summary, see http://www.unmarried.org/common.html ). All states will recognize a common law marriage if it was validly established in another state pursuant to full faith and credit principles.
However, Louisiana is not a state that recognizes common law marriage, so living together in the State of Louisiana is insufficient to establish a marriage. Louisiana is a community property state (along with Alaska, Arizona, California, Idaho, Nevada, New Mexico, Puerto Rico, Texas, Washington, and Wisconsin) but those laws will not be triggered unless an actual marriage license is obtained.
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