The process of putting capital into fixed form could hardly go on forever, and several events led to a final crash. In 1871 and 1872 great fires in Chicago and Boston destroyed millions of dollars' worth of property. Early in 1873 the government investigation of the Credit Mobilier Company led to widespread distrust of the roads and made investors conservative about buying bonds. On September 18, 1873, Jay Cooke and Company found itself unable to continue business and closed its doors. The failure was a thunderbolt to the financial world. Indeed, so unbelievable was the news that an energetic policeman arrested a small newsboy who shouted his "Extra--All about the failure of Jay Cooke." If Jay Cooke and Company fell, the sky might fall. People rushed to withdraw their funds from the banks. Fisk and Hatch opened their doors for fifteen minutes and received calls for $1,500,000. They closed at once. The smaller financial institutions followed the bigger ones. Stocks fell, the Exchange was closed, there was a money famine. Industrial concerns, dependent on the banks, failed by scores. Industrial paralysis, with railroad receiverships, laborers out of employment, riots and their accompaniments, showed how deep-seated had been the trouble. Not until late in the decade did business recover its former prosperity. With the return of more stable conditions the construction of railroads continued unabated. The Northern Pacific ran near the Canadian line and connected the upper Mississippi Valley with the coast, carrying in its trail the manners and customs of the East. Two lines in the South were extended to the Pacific, so that by the middle eighties four great main avenues gave passage through a region over which, so recently, the miner and the trapper had forced a dangerous path. The fact that it was often necessary, in building the railroads across the plains, to detail half the working force to protect the remainder against the Indians, calls attention to one unmistakable result of the conquest of the Far West. The construction of the railroads spelled the doom of the wild Indian. Far back in 1834 the government had adopted the policy of setting aside large tracts of land west of the Mississippi for the use of the Indian tribes. Most of the savages had been stationed in an immense area between southern Minnesota and Texas, while other smaller reservations had been scattered over most of the states west of the river. On the whole, the government had dealt with the Indians in tribes, not as individuals. The rapid inflow of population to the fertile lands, together with the rush of prospectors to newly discovered supplies of gold and silver, caused increasing demands from the Indians for protection, and from the whites for the extinguishment of Indian land titles.