Revolutions of 1848 in the Austrian Empire even socialist currents resisted the Empire's longstanding conservatism. The events of 1848 were the product of mounting social and political tensions after the Congress of Vienna of 1815. During the "pre-March" period, the already conservative Austrian Empire moved further away from ideas of the Age of Enlightenment, restricted freedom of the press, limited many university activities, and banned fraternities. Conflicts between debtors and creditors in agricultural production as well as over land use rights in parts of Hungary led to conflicts that occasionally erupted into violence. Conflict over organized religion was pervasive in pre-1848 Europe. Tension came both from within
Diseases and epidemics of the 19th century 1854, it entered Venezuela; Brazil also suffered in 1855. The fourth cholera pandemic (1863–1875) spread mostly in Europe and Africa. At least 30,000 of the 90,000 Mecca pilgrims died from the disease. Cholera ravaged northern Africa in 1865 and southeastward to Zanzibar, killing 70,000 in 1869–70. Cholera claimed 90,000 lives in Russia in 1866. The epidemic of cholera that spread with the Austro-Prussian War (1866) is estimated to have taken 165,000 lives in the Austrian Empire. In 1867, 113,000 lost their lives to cholera in Italy. and 80,000 in Algeria. Outbreaks in North America in 1866–1873 killed some 50,000 Americans.