In addition , Owen was appointed as a U.S. geologist in 1839 .
In addition , Owen was led federal surveys of Iowa , Wisconsin , and northern Illinois ( 1839 -- 40 ) and in the Upper Midwest ( 1847 - 1851 ) .
In addition , Owen was appointed as a U.S. geologist in 1839 and led federal surveys of Iowa , Wisconsin , and northern Illinois ( 1839 -- 40 ) and in the Upper Midwest ( 1847 - 1851 ) .