The principle of government by law.
The First Transcontinental Railroad (also called the Great Transcontinental Railroad, known originally as the "Pacific Railroad" and later as the "Overland Route") was a 1,912-mile (3,077 km) continuous railroad line constructed between 1863 and 1869 that connected the existing eastern U.S. rail network at Omaha, Nebraska/Council Bluffs, Iowa with the Pacific coast at the Oakland Long Wharf on San Francisco Bay.[1] The rail line was built by three private companies over public lands provided by extensive US land grants.[2] Construction was financed by both state and US government subsidy bonds as well as by company issued mortgage bonds.[3][4][5][N 1] The Western Pacific Railroad Company built 132 mi (212 km) of track from Oakland/Alameda to Sacramento, California. The Central Pacific Railroad Company of California (CPRR) constructed 690 mi (1,110 km) eastward from Sacramento to Promontory Summit, Utah Territory (U.T.). The Union Pacific built 1,085 mi (1,746 km) from the road's eastern terminus at Council Bluffs near Omaha, Nebraska westward to Promontory Summit.[7][8][9]
The railroad opened for through traffic on May 10, 1869 when CPRR President Leland Stanford ceremonially drove the gold "Last Spike" (later often referred to as the "Golden Spike") with a silver hammer at Promontory Summit.[10][11] The coast-to-coast railroad connection revolutionized the settlement and economy of the American West. It brought the western states and territories into alignment with the northern Union states and made transporting passengers and goods coast-to-coast considerably quicker and less expensive.
Paddle steamers linked Sacramento to the cities and their harbor facilities in the San Francisco Bay until 1869, when the CPRR completed and opened the WP grade (which the CPRR had acquired control of in 1867–68 [N 2][N 3]) to Alameda and Oakland.
The first transcontinental rail passengers arrived at the Pacific Railroad's original western terminus at the Alameda Mole on September 6, 1869 where they transferred to the steamer Alameda for transport across the Bay to San Francisco. The road's rail terminus was moved two months later to the Oakland Long Wharf about a mile to the north.[15][16][N 4] Service between San Francisco and Oakland Pier continued to be provided by ferry.
The CPRR eventually purchased 53 miles (85 km) of UPRR-built grade from Promontory Summit (MP 828) to Ogden, U.T. (MP 881), which became the interchange point between trains of the two roads. The transcontinental line was popularly known as the Overland Route after the principal passenger rail service that operated over the length of the line until 1962.[19]
The leaders who spread Islam after Muhammad's death were Abu Bakr, Umar, Uthman, and Ali. If you want the answer from a website, I suggest going here
--> http://peopleof.oureverydaylife.com/led-islamic-world-after-muhammad-died-7743.html <-- I hope this answer helps you.
Answer:
Because they had to be with their families first
