What factors helped happen establish itself as one of the world leaders in industrial production during the second half of the twentieth century?

By 1900, the United States was manufacturing about 30 percent of the world's industrial goods, surpassing Britain as the leading industrial nation.

Also advancements in manufacturing and production technology fastened the enabling of the widespread adoption of technological systems such as telegraph and railroad networks, gas and water supply, and sewage systems, which had earlier been concentrated to a few select cities. The enormous expansion of rail and telegraph lines after 1870 allowed unprecedented movement of people and ideas, which culminated in a new wave of globalization. In the same time period, new technological systems were introduced, most significantly electrical power and telephones.

what is the tax base for the sales tax?

it should be (usually ) 6%