Following the completion of the Pacific Railroad Surveys in 1855, several national proposals to build a transcontinental railroad failed because of the energy consumed by political disputes over slavery. With the secession of the South in 1861, the modernizers in the Republican Party controlled the US Congress. They passed legislation in 1862 authorizing the central rail route with financing in the form of land grants and government railroad bond, which were all eventually repaid with interest. The government and the railroads both shared in the increased value of the land grants, which the railroads developed. The construction of the railroad also secured for the government the economical "safe and speedy transportation of the mails, troops, munitions of war, and public stores."