State tax filing

You are still a Wisconsin resident.  It is true you didn't spend much time there, but being away at school is considered a temporary absence from your home for tax purposes.  

Do you need to file a Wisconsin return?  If your income is above the Wisconsin filing threshold, then, yes, you will be required to do so.  If your parents cannot claim you (although they probably can), you do not have to file in Wisconsin if you were single and had less than $11,280 of income.  If you are claimed, you don't need to file if you meet the following requirements (On Wisconsin's DOR website, at the following link: Wisconsin Filing Threshold

• If you (or your spouse) can be claimed as a dependent on someone else's tax return, you are required to file a Wisconsin return if either of the following applies:
  1. You have gross income of more than $1,050 and it includes at least $351 of unearned (non-wage) income, or
  2. You have gross income (total unearned income and earned income combined) of more than:
     
     • $10,580 if single
     • $19,580 if married filing jointly
     • $9,300 if married filing separately
     • $13,660 if head of household

  Unearned income includes taxable interest, dividends, capital gain distributions, and taxable scholarship and fellowship grants that were not reported on a Form W-2 (wage statement). Earned income includes wages, tips, and taxable scholarship and fellowship grants that were reported to you on a Form W-2.

• Also, if you owe a Wisconsin penalty on an IRA, retirement plan, Coverdell education savings account, medical savings account, health savings account, or Archer medical savings account, you are required to file a tax return.

If your income is below the above amounts, you will not be required to file a Wisconsin return (but may choose to do so if Wisconsin taxes have been withheld at either of your two jobs).

You will need to file nonresident returns for Minnesota and North Carolina.  Prepare these first, because if you are required to file a Wisconsin return, Wisconsin will provide you a tax credit for taxes paid to both of those states for the income you earned there.