1860s. Meanwhile, the lumber industry dominated in the heavily forested northern sections of Wisconsin, and sawmills sprang up in cities like La Crosse, Eau Claire, and Wausau. These economic activities had dire environmental consequences. By the close of the 19th century, intensive agriculture had devastated soil fertility, and lumbering had deforested most of the state. These conditions forced both wheat agriculture and the lumber industry into a precipitous decline. Beginning in the 1890s, farmers in Wisconsin shifted from wheat to dairy production in order to make more sustainable and profitable use of their land. Many immigrants carried cheese-making traditions that, combined with the state's suitable geography and dairy research led by Stephen Babcock at the University of Wisconsin, helped the state build a reputation as "America's Dairyland". Meanwhile, conservationists including Aldo Leopold helped re-establish the state's forests during the early 20th century, paving the way for a more renewable lumber and paper milling industry as well as promoting recreational tourism in the northern woodlands. Manufacturing also boomed in Wisconsin during the early 20th century, driven by an immense immigrant workforce arriving from Europe. Industries in cities like Milwaukee ranged from brewing and food processing to heavy machine production and tool-making, leading Wisconsin to rank 8th among U.S. states in total product value by 1910. 20th century The early 20th century was also notable for the emergence of progressive politics championed by Robert M. La Follette. Between 1901 and 1914, Progressive Republicans in Wisconsin created the nation's first comprehensive statewide primary election system, the first effective workplace injury compensation law, and the first state income tax, making taxation proportional to actual earnings. The progressive Wisconsin Idea also promoted the statewide expansion of the University of Wisconsin through the UW-Extension system at this time. Later, UW economics professors John R. Commons and Harold Groves helped Wisconsin create the first unemployment compensation program in the United States in 1932. In the immediate aftermath of World War II, citizens of Wisconsin were divided over issues such as creation of the United Nations, support for the European recovery, and the growth of the Soviet Union's power. However, when Europe divided into Communist and capitalist camps and the Communist revolution in China succeeded in 1949, public opinion began to move towards support for the protection of democracy and capitalism against Communist expansion. Wisconsin took part in several political extremes in the mid to late 20th century,