In the eighteenth century and in British common law earlier, marriage did have legal financial consequences - the wife's property became her husband's, and legitimate children inherited and illegitimate did not.
You could, of course, make various settlements and wills, within limits.
Was the state involved in issuing a license to the married couple in the examples you cite? From my reading, Southern states in the US started issuing marriage licenses to recognize only the marriages that they approved of - the ones that did not involve a white person and a black person.