Change from non-immigrant visa to immigrant visa, possible?

To change from a visitor visa while in the USA is impossible, to get an immigration visa you need to apply for immigration from your country of origin and be in one of several categories to even be considered. Such as employable in an essential service that lacks workers, teaching degrees already cleared by an American institute and an offer of employment. Nurse or Doctor already cleared! If immigration and border services even suspects you are using a visitor visa to gain entry to then work and stay they can and will send you packing. Unemployment is at an all time high in the USA right now times are tough.

If you are an American citizen and can support your husband until he can find a job you can re enter the USA and he can apply to come over as a dependent with no right to work or seek employment. He can also apply to become a landed immigrant with you sponsoring him as his spouse, but you must be there and set up in a residence and a job etc. Check out on the US federal gov't web sites all the information is there.

Here is the info for changing non immigrant status.