Will my old T28 world phone work with prepaid sims?

I am currently on a plan in Canada, but will be moving back to the US
this fall and in the mean time will be making several trips back and
forth. I was thinking I could get a US prepaid sim card for my T28 to
use while I am stateside. Is this possible, if so which carrier should
I use. Also, is this the best option?

Any information appreciated!
Tracy

Yes, it has been unlocked. Thanks!