Dumas family move to Alabama

It is very interesting that most of the Dumas family moved from Manitowoc County, Wisconsin to Alabama. I know of other Kiehl family who moved in the 1920's ad 1930's to the south. Is there some source of income that drew them to the southern part of the US? I have a Christmas greeting card from Jamida Dumas in 1949. I feel this is a relative. Any thoughts on this?