The internment of Japanese-Americans was immoral and unnecessary, the use of census information in wartime to track enemy aliens was less problematic than the internment of Japanese-Americans who were American citizens. The law allowing the use of the census data was passed in 1942 and repealed in 1947.
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However, Sherman had every legal right to get census data on farmland (not persons) in any even he used information from state of georgia quoting sherman
"I had obtained not only the United States census-tables of 1860," Sherman wrote in his Memoirs, "but a compilation made by the Controller of the State of Georgia for the purpose of taxation, containing in considerable detail the 'population and statistics' of every county in Georgia" (Sherman)."
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