How do I go about marrying my fiancé in Buffalo County, Nebraska jail?

Wait until he's released?

You'd have to check out the laws in your state, and talk to the prison as well. What you're asking would take a heck of a lot of research. So it really depends on how badly you want to marry him, and how much effort you're willing to put forth to do so. Start calling and researching to find the answer. I doubt anyone will do that sort of work for free.

Good luck.

You will have to ask the county sheriff is this is allowed. Normally because of security, weddings are not allowed in the jails.

Most State prisons will allow it for inmates in on longer terms. The reasons in jail, the inmate in jail is there shorter term, a jail sentence is always less than one year.

** if this is a very large jail, talk to the Chaplain office. They arrange the weddings normally