When I sought legal counsel to apply for a greencard I was told that an immediate family member (Mother, Father, sister, brother, son, daughter), could sponsor me if they were living legally in the US. Your son could sponsor you with the appropriate paperwork.
I'm a Canadian living in the U.S. on a student visa. My fiance has a gun charge on his record from the past and has served his time. (I believe a year?)
If we marry here, as I doubt he can get across the border to marry in Canada, will he have to go through exactly the same process...