I am not in prison. I am just trying to understand how someone in this country can be imprisoned for a debt. (And yes, people are imprisoned everyday in this country for debts.)

Sorry, but I'm not aware of that happening, with the exception of child support and tax evasion

In Texas, it is possible to be jailed for contempt of court if a judgment debtor fails to make payment as agreed under an agreed judgment. It's not technically jail for the debt, but contempt of court.

The contempt exists because of the debt. So...one would in fact be jailed because of the debt.