In the early nineteenth century, Missouri played a central role in attracting Germans to the Midwest, perhaps most notably through Gottfried Duden's widely read Report on a Journey to the Western States of North America. Duden traveled to America in 1824 with a professional farmer and cook to work the land he purchased near what is now Dutzow, Missouri. He spent his days visiting the lead mines, duck hunting with Nathan Boone, and observing nature. His idyllic accounts, written in the form of personal letters, covered many topics, from slavery and Indians to farming methods and weather. Duden returned to Germany in 1827, and in 1829 he self-published 1, 500 copies of his "letters home, " praising the virtues of Missouri for those wishing to be farmers or businessmen. By 1840, more than 38, 000 Germans had settled in the lower Missouri River valley, and German immigrants to Missouri were often called "followers of Duden.