Abbreviations for place names can change over time. What is used for a location today may not be what was used one hundred years ago. Sometimes old forms fall out of use or governmental or postal regulations change the “standard” abbreviation. Some census takers or other record officials make their own abbreviations when they tire of writing the same location over and over. Self-made abbreviations may be unique to the creator and are best analyzed with local geographic names in mind.
Sometimes two location can have the same abbreviation. In some US census records Canada and California are both abbreviated “Ca.” Others chose to abbreviate it as “Can.”
And sometimes Indiana was abbreviated as “Ia.” Today that’s the state of Iowa. But if you see it in an 1850 census enumeration for someone living in Indiana,chances are it means Indiana. Probably.
And do not abbreviate yourself. Take the time to write out the entire place name. Same someone else the confusion