[Godzilla]

There are times in a society when polygamy or polyandry are necessary for survival however once those forces are abated if you will find that people prefer to go back to the one man, one woman norm.

I would venture to guess that the United States from the 1830's to 1897 was not one of those period of survival.

[Harmless Teddy Bear]

It depends.

I know that following the Civil War there were a lot more females around then males. It was not uncommon for a guy to have a wife and a couple of more ladies around the place who were known as "cousins".

It was better then working in a brothal and less uncertain then becoming a mail order bride.

Out West where the problem was not enough women you had the situation the other way around.