Final answer:
The general trend in pig iron production from 1720 to 1860 was an upward trajectory, aligning with the advancements of the Industrial Revolution. Increased industrial output, innovations in manufacturing, and technological progress contributed to the elevation of iron production and subsequent steel production, particularly in the United States.
Step-by-step explanation:
Between the years of 1790 and 1830, there is no exact data provided for the increase in pig iron production in tons. However, it is evident that throughout the longer period of 1720 to 1860, the general trend in pig iron production was upwards. This increase fits within the broader context of the Industrial Revolution, which brought about significant technological advancements and increases in various types of industrial production, including iron and steel.
In particular, the late 18th century and early 19th century were marked by innovative developments in industrial manufacturing, such as the introduction of steam power and the increased use of iron as a building material. These industrial changes laid the foundation for great strides in iron production, as evidenced by historical accounts of China's Song dynasty, which by 1100 had already significantly increased its iron output.
By the year 1860, steel production in the United States, which is directly related to iron production, reached thirteen thousand tons. It continued to skyrocket in the following decades, cementing steel's role in the economy. As production rose to meet heavy demand, prices fell, allowing industries such as construction and automotive to thrive thanks to affordable, high-quality steel.