A rapid means of long-distance transportation became a necessity for the United States as settlement spread farther westward. For a long time the railroad companies met with troubled mechanical problems. The most (1) ______ serious were the construction of rails able to bear the load, and the development of the safe, effective stopping system. Once these were solved, (2) ______ and the railroad was established as the best means of land transportation. (3) ______ By 1860 they had built thousands of miles of railroads crossing the eastern mountain ranges and reaching westward in the Mississippi. The high point in railroad building came by the construction of the (4) ______ first transcontinental railroad. In 1862 Congress had authorized two (5) ______ railroad companies to build lines from Nebraska westward and from California eastward to a meeting point so as to complete a transcontinental system. The Central Pacific Company, starting from California, used Chinese labor, the Union Pacific employed crews of Irish laborers. (6) ______ The two groups worked at remarkable speed, each tried to cover a (7) ______ greater distance than the other. In 1869, they met at a place called Promontory. Many visitors came there for the great occasion. There were joyous celebrations all over the country, with parades and the ringing of church bells honor the great achievement. (8) ______ The railroad was very important in discouraging westward movement. (9) ______ It also helped build up industry and fanning by moving raw materials and by distributing products rapid to distant markets. (10) ______