State Taxes

I'm sorry to post again. 

But if I'm selling products online to all 50 states, would I then have to file state tax returns for those states? 

Example: I live in CA and that is where my business would be out of.

Would I have to only file a tax return in CA? Or would I have to keep track of tax rates in all of the other states and then file multiple returns at the end of the year?

Thank you!