Outlawed slavery in the territory
On May 10, 1869, at Promontory Point, Utah, workers drove a spike that linked two rail lines, one snaking from the East, the other from California, completing America's first transcontinental railroad. This event helped launch an era of economic development that would transform a Jeffersonian society of yeoman farmers into an industrial powerhouse.
My option is that the closer they are to their sources of energy the more they produce and more materials to complete their product.
Answer:
1807
During this century more than half of the total, amounting to an average of about 50,000 enslaved Africans per year, was transported, mostly from the end of the Seven Years' War in 1763 until the end of the British trade in 1807.
