annebest45 on Family Tree Circles

James dent was living in Milwaukee, Wisconsin by 1850. His wife was Eliza - variously spelled Witzendof, Wittenden etc. There were two daughters, Sara b. about 1849 and Rosaline b. about 1860 both born in Milwaukee. The family arrived in Melbourne, Australia around 1861. I would like information on where they came from and how/why they left America and arrived in Australia and what happened to them in Australia.
The US census of 1850 records James Dent 33, born in England, Shoemaker, living in Ward 1 District, Milwaukee in a house valued at $1,000 with his wife Eliza 32, born in Germany, and children Mary A, 12, born in England, Elizabeth 7, born in New York and Sarah -1, born in Wisconsin.
Can anyone help with this?