Alexander Nelson

I am still looking for any information on Alexander Nelson. I know his father was Benjamin Nelson. Alexander was born around 1839 and married Jane Testrow in 1869. Jane later married William Campbell in 1886. I can't find any trace of what happened with Alexander. Iknow that Alexander & Jane were living in South Aust and that when Jane remarried she was living in Bordertown SA. Please if anyone has any info on Alexander I would greatly appreciate it.